SECURITIES AND EXCHANGE COMMISSION

                             WASHINGTON, D.C. 20549

                                  SCHEDULE 13G/A

                    Under the Securities Exchange Act of 1934

                                (Amendment No. 4)

                                Alamo Group, Inc.
                            ----------------------
                                (Name of issuer)

                     Common Stock, $.10 par value per share
                     ---------------------------------------
                         (Title of class of securities)

                                    011311107
                                  ------------
                                 (CUSIP number)

The  remainder  of this cover page shall be filled out for a reporting  person's
initial filing on this form with respect to the subject class of securities, and
for any  subsequent  amendment  containing  information  which  would  alter the
disclosures provided in a prior cover page.

The information required in the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the  Securities  Exchange  Act of
1934 ("Act") or otherwise  subject to the liabilities of that section of the Act
but  shall be  subject  to all other  provisions  of the Act  (however,  see the
notes).



--------------------------------------------------------------------------------
  1       NAME OF REPORTING PERSONS
          S.S. OR I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS

          EQSF Advisers, Inc.
          (EIN 13-3354359)
--------------------------------------------------------------------------------
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  2       CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*          (a)  [   ]
                                                                     (b)  [   ]
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
  3       SEC USE ONLY
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
  4       CITIZENSHIP OR PLACE OF ORGANIZATION

          New York Corporation

--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
                                  5      SOLE VOTING POWER
                                              1,662,700

           NUMBER OF            ------------------------------------------------
                                ------------------------------------------------
            SHARES                6      SHARED VOTING POWER
         BENEFICIALLY                        None

           OWNED BY             ------------------------------------------------
                                ------------------------------------------------
             EACH                 7      SOLE DISPOSITIVE POWER
                                             1,662,700

             WITH               ------------------------------------------------
                                ------------------------------------------------
                                  8       SHARED DISPOSITIVE POWER
                                             None

--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
 9        AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

                 1,662,700

--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
 10       CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*
                                                                      [ ]
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
 11       PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)
              17.06%

--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
          TYPE OF REPORTING PERSON*
 12
                   IA

--------------------------------------------------------------------------------

                      *SEE INSTRUCTIONS BEFORE FILLING OUT!




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  1       NAME OF REPORTING PERSONS
          S.S. OR I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS

          M.J. Whitman Advisers, Inc.

          (EIN 13-3686379)

--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
  2       CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*          (a)  [   ]
                                                                     (b)  [   ]
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
  3       SEC USE ONLY
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
  4       CITIZENSHIP OR PLACE OF ORGANIZATION
               New York Corporation

--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
                                  5      SOLE VOTING POWER
                                              144,050

           NUMBER OF            ------------------------------------------------
                                ------------------------------------------------
            SHARES                6      SHARED VOTING POWER
         BENEFICIALLY

           OWNED BY                           None
                                ------------------------------------------------
                                ------------------------------------------------
             EACH                 7      SOLE DISPOSITIVE POWER
                                             196,900

                                ------------------------------------------------
                                ------------------------------------------------
             WITH                 8       SHARED DISPOSITIVE POWER
                                                None

--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
 9        AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

                196,900

--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
 10       CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*
                                                                 [ ]
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
 11       PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)
                    2.02%

--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
          TYPE OF REPORTING PERSON*
 12
                   IA

--------------------------------------------------------------------------------

                      *SEE INSTRUCTIONS BEFORE FILLING OUT!




--------------------------------------------------------------------------------
  1       NAME OF REPORTING PERSONS
          S.S. OR I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS

                   Martin J. Whitman


--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
  2       CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*       (a)   [   ]
                                                                  (b)   [   ]
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
  3       SEC USE ONLY
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
  4       CITIZENSHIP OR PLACE OF ORGANIZATION
                    USA

--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
                                  5      SOLE VOTING POWER
           NUMBER OF                              None  (See Item 4)
                                ------------------------------------------------
                                ------------------------------------------------
                                  6      SHARED VOTING POWER
           SHARES                                  None
         BENEFICIALLY

           OWNED BY             ------------------------------------------------
                                ------------------------------------------------
             EACH                 7      SOLE DISPOSITIVE POWER
                                                 None  (See Item 4)
                                ------------------------------------------------
                                ------------------------------------------------
          PERSON WITH            8       SHARED DISPOSITIVE POWER
                                                  None

--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
 9        AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

                   -0-    (See Item 4)

--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
 10       CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*
                                                                          [ ]
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
 11       PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)
               -0-

--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
 12       TYPE OF REPORTING PERSON*

                   IN

--------------------------------------------------------------------------------
                      *SEE INSTRUCTIONS BEFORE FILLING OUT!

Item 1.

         (a)      NAME OF ISSUER:
                  ---------------
                  Alamo Group, Inc. (the "Issuer").

         (b)      ADDRESS OF ISSUER'S PRINCIPAL EXECUTIVE OFFICES OR, IF NONE,
                  RESIDENCE:
                  --------------------------------------------------------------
                    1502 East Walnut, Sequin, TX 78155
Item 2.

         (a)      NAME OF PERSON FILING:
                  ----------------------

                  This schedule is being jointly filed by EQSF Advisers,  Inc.
("EQSF"),  M.J.  Whitman  Advisers,  Inc.  ("MJWA") and Martin J. Whitman,  the
Chief Executive  Officer of EQSF and MJWA and controlling  person of EQSF and
MJWA.  (EQSF,  MJWA and Martin J.Whitman  are  sometimes  collectively referred
to  hereinafter  as  "Filer").  Attached  hereto as an  exhibit is a copy of
the jointSchedule 13G filing agreement among the reporting persons.

         (b)      ADDRESS OF PRINCIPAL BUSINESS OFFICE:
                  -------------------------------------

                  The address of the principal  executive  office of EQSF,  MJWA
 and Mr.  Whitman is: 767 Third Avenue,  New York,  New York 10017-2023.

         (c)      CITIZENSHIP:
                  ------------

                  The  citizenship  or  place  of  organization  of  each of the
reporting persons is as follows:

                  EQSF

                  ----
                  New York State Corporation.


                  MJWA

                  ----
                  New York State Corporation.


                  MARTIN J. WHITMAN
                  -----------------
                  United States Citizen.


         (d)      TITLE OF CLASS OF SECURITIES:
                  -----------------------------
                  Common Stock, $.10 par value per share.

         (e)      CUSIP NUMBER:
                  -------------
                  011311107

Item 3. IF THIS  STATEMENT  IS  BEING  FILED  PURSUANT  TO  RULES  13D-1(B),  OR
13D-2(B), CHECK WHETHER THE PERSON FILING IS A:

-----------------------------------------------------------------------

                  (e)   Investment  Adviser  registered under section 203 of the
                        Investment Advisers Act of 1940 (EQSF and MJWA).

Item 4.  OWNERSHIP.
         ---------

                (a)&(b) EQSF  beneficially  owns 1,662,700  shares, or
                        17.06% of the  class of  securities  of the  issuer.
                        MJWA  beneficially  owns 196,900 shares, or 2.02% of
                        the class of securities of the issuer.

                  (c)  (i) EQSF: 1,662,700
                           MJWA: 144,050


                        (ii) Not applicable.

                       (iii) EQSF: 1,662,700
                             MJWA:  196,900


                       (iv) Not applicable.

         Mr. Whitman disclaims beneficial ownership of all such shares.

Item 5.  Ownership of Five Percent or Less of a Class.
         ---------------------------------------------
                  Not applicable.


Item 6.  Ownership of More than Five Percent on Behalf of Another Person.
         ----------------------------------------------------------------
                  Third  Avenue Value Fund,  an  investment  company  registered
under the  Investment  Company Act of 1940,  has the right to receive  dividends
from, and the proceeds from the sale of, 594,300 of the shares reported by EQSF,
Third Avenue  Small-Cap Value Fund, an investment  company  registered under the
Investment Company Act of 1940, has the right to receive dividends from, and the
proceeds from the sale of, 319,500 of the shares reported by EQSF,  Third Avenue
Value Portfolio of the WRL Series Fund, an investment  company  registered under
the Investment Company Act of 1940, has the right to receive dividends from, and
the  proceeds  from the sale of,  82,900 of the shares  reported by EQSF,  Style
Select Series Small-Cap Value Portfolio,  an investment company registered under
the Investment Company Act of 1940, has the right to receive dividends from, and
the  proceeds  from the sale of,  50,000 of the shares  reported by EQSF,  Third
Avenue Value  Portfolio of the Third Avenue Variable Series Trust, an investment
company  registered  under the Investment  Company Act of 1940, has the right to
receive  dividends  from, and the proceeds from the sale of,  36,000,  and Style
Select Series Focused Value Portfolio,  an investment  company  registered under
the Investment Company Act of 1940, has the right to receive dividends from, and
the proceeds from the sale of, 580,000 of the shares  reported by EQSF.  Various
clients  for whom  MJWA acts as  investment  advisor  have the right to  receive
dividends from, and the proceeds of the sale of, the shares reported by MJWA.

Item 7. Identification and Classification of the Subsidiary Which Acquired the
        Security Being Reported on By the Parent Holding Company.
        ------------------------------------------------------------------------

                  Not Applicable.

Item 8.  Identification and Classification of Members of the Group.
         ----------------------------------------------------------
                  Not applicable.

Item 9.  Notice of Dissolution of Group.
         -------------------------------
           Not applicable.

Item 10. Certification.
         --------------
                  By signing  below I certify  that, to the best of my knowledge
and  belief,  the  securities  referred to above were  acquired in the  ordinary
course of business  and were not acquired for the purpose of and do not have the
effect of changing or influencing  the control of the issuer of such  securities
and were not acquired in connection  with or as a participant in any transaction
having such purposes or effect.



                                    SIGNATURE

                  After  reasonable  inquiry and to the best of my knowledge and
belief,  I certify  that the  information  set forth in this  statement is true,
complete and correct.

                                                 April 11, 2001
                                            -----------------------
                                              (Date)




                                            EQSF ADVISERS, INC.

                                            By:/s/ MARTIN J. WHITMAN
                                            --------------------------
                                            Martin J. Whitman
                                            Chairman, President and
                                            Chief Executive Officer


                                            M.J. WHITMAN ADVISERS, INC.

                                            By:/s/ MARTIN J. WHITMAN
                                            --------------------------
                                            Martin J. Whitman
                                            Chairman and Chief Executive Officer

                                            /s/  MARTIN J. WHITMAN
                                            --------------------------
                                            Martin J. Whitman, President