In the Masterstartup.bat you will find the call out for a change directory to the sounds folder and then call the bat file ETOMusicSwapper.bat file
.(in red)
@ECHO OFF
CLS
CALL ETOEraSwapper.bat
CD "C:\Program Files (x86)\Microsoft Games\CFS3 ETO Expansion\global_layer"
CALL ETOGLSwapper.bat
CD "C:\Program Files (x86)\Microsoft Games\CFS3 ETO Expansion\sounds"
CALL ETOMusicSwapper.bat
START cfs3.exe
In the ETOMusicSwapper.bat file the file will then look for the not present year qclocations.xml file, go to file rename paragraph associated with that year and then change the name of that years file to uimusic.wav through a couple of rename processes.
It might be best for you to remove all *.uimusic.wav files and reinstall all the etomusicswapper uimusic files
Sorry it took awhile I had to re-educate myself as it has been a few years since I have fiddled and fired up CFS3.
@ECHO OFF
CLS
ECHO.
ECHO.
ECHO WELCOME TO THE CFS3 ETO EXPANSION MUSIC SWAPPER
ECHO.
ECHO.
ECHO.

RESENT
IF NOT EXIST "C:\Program Files (x86)\Microsoft Games\CFS3 ETO Expansion\1945_qclocations.xml" GOTO :1945_ERA
IF NOT EXIST "C:\Program Files (x86)\Microsoft Games\CFS3 ETO Expansion\1944_qclocations.xml" GOTO :1944_ERA
IF NOT EXIST "C:\Program Files (x86)\Microsoft Games\CFS3 ETO Expansion\1943_qclocations.xml" GOTO :1943_ERA
IF NOT EXIST "C:\Program Files (x86)\Microsoft Games\CFS3 ETO Expansion\bob_qclocations.xml" GOTO :BOB_ERA
IF NOT EXIST "C:\Program Files (x86)\Microsoft Games\CFS3 ETO Expansion\1936_qclocations.xml" GOTO :1936_ERA
:1936_ERA
IF NOT EXIST bob_uimusic.wav GOTO :BOB_1936GL
IF NOT EXIST 1943_uimusic.wav GOTO :1943_1936GL
IF NOT EXIST 1944_uimusic.wav GOTO :1944_1936GL
IF NOT EXIST 1945_uimusic.wav GOTO :1945_1936GL
IF NOT EXIST 1936_uimusic.wav GOTO :END
:BOB_ERA
IF NOT EXIST 1936_uimusic.wav GOTO :1936_BOBGL
IF NOT EXIST 1943_uimusic.wav GOTO :1943_BOBGL
IF NOT EXIST 1944_uimusic.wav GOTO :1944_BOBGL
IF NOT EXIST 1945_uimusic.wav GOTO :1945_BOBGL
IF NOT EXIST bob_uimusic.wav GOTO :END
:1943_ERA
IF NOT EXIST 1936_uimusic.wav GOTO :1936_1943GL
IF NOT EXIST bob_uimusic.wav GOTO :BOB_1943GL
IF NOT EXIST 1944_uimusic.wav GOTO :1944_1943GL
IF NOT EXIST 1945_uimusic.wav GOTO :1945_1943GL
IF NOT EXIST 1943_uimusic.wav GOTO :END
:1944_ERA
IF NOT EXIST 1936_uimusic.wav GOTO :1936_1944GL
IF NOT EXIST bob_uimusic.wav GOTO :BOB_1944GL
IF NOT EXIST 1943_uimusic.wav GOTO :1943_1944GL
IF NOT EXIST 1945_uimusic.wav GOTO :1945_1944GL
IF NOT EXIST 1944_uimusic.wav GOTO :END
:1945_ERA
IF NOT EXIST 1936_uimusic.wav GOTO :1936_1945GL
IF NOT EXIST bob_uimusic.wav GOTO :BOB_1945GL
IF NOT EXIST 1943_uimusic.wav GOTO :1943_1945GL
IF NOT EXIST 1944_uimusic.wav GOTO :1944_1945GL
IF NOT EXIST 1945_uimusic.wav GOTO :END
:QUIT_MENU
GOTO :END
:BOB_1936GL
REN uimusic.wav bob_uimusic.wav
REN 1936_uimusic.wav uimusic.wav
GOTO END
:1943_1936GL
REN uimusic.wav 1943_uimusic.wav
REN 1936_uimusic.wav uimusic.wav
GOTO END
:1944_1936GL
REN uimusic.wav 1944_uimusic.wav
REN 1936_uimusic.wav uimusic.wav
GOTO END
:1945_1936GL
REN uimusic.wav 1945_uimusic.wav
REN 1936_uimusic.wav uimusic.wav
GOTO END
:1936_BOBGL
REN uimusic.wav 1936_uimusic.wav
REN bob_uimusic.wav uimusic.wav
GOTO END
:1943_BOBGL
REN uimusic.wav 1943_uimusic.wav
REN bob_uimusic.wav uimusic.wav
GOTO END
:1944_BOBGL
REN uimusic.wav 1944_uimusic.wav
REN bob_uimusic.wav uimusic.wav
GOTO END
:1945_BOBGL
REN uimusic.wav 1945_uimusic.wav
REN bob_uimusic.wav uimusic.wav
GOTO END
:1936_1943GL
REN uimusic.wav 1936_uimusic.wav
REN 1943_uimusic.wav uimusic.wav
GOTO END
:BOB_1943GL
REN uimusic.wav bob_uimusic.wav
REN 1943_uimusic.wav uimusic.wav
GOTO END
:1944_1943GL
REN uimusic.wav 1944_uimusic.wav
REN 1943_uimusic.wav uimusic.wav
GOTO END
:1945_1943GL
REN uimusic.wav 1945_uimusic.wav
REN 1943_uimusic.wav uimusic.wav
GOTO END
:1936_1944GL
REN uimusic.wav 1936_uimusic.wav
REN 1944_uimusic.wav uimusic.wav
GOTO END
:BOB_1944GL
REN uimusic.wav bob_uimusic.wav
REN 1944_uimusic.wav uimusic.wav
GOTO END
:1943_1944GL
REN uimusic.wav 1943_uimusic.wav
REN 1944_uimusic.wav uimusic.wav
GOTO END
:1945_1944GL
REN uimusic.wav 1945_uimusic.wav
REN 1944_uimusic.wav uimusic.wav
GOTO END
:1936_1945GL
REN uimusic.wav 1936_uimusic.wav
REN 1945_uimusic.wav uimusic.wav
GOTO END
:BOB_1945GL
REN uimusic.wav bob_uimusic.wav
REN 1945_uimusic.wav uimusic.wav
GOTO END
:1943_1945GL
REN uimusic.wav 1943_uimusic.wav
REN 1945_uimusic.wav uimusic.wav
GOTO END
:1944_1945GL
REN uimusic.wav 1944_uimusic.wav
REN 1945_uimusic.wav uimusic.wav
:END
CD "C:\Program Files (x86)\Microsoft Games\CFS3 ETO Expansion"