This afternoons project the MTH Scale Test Car....no drills, no screws, no shims. Needed good files and Dremel, and screw driver to take out 2 screws. 2 screws holds this whole car together. Make the coupler opening bigger and grind down the boss the holds the claw on. Put the Kadees in then screw the base down tight. The base clamps the Kadee in place.
The top photo shows how much larger you have to make the opening, don't file the top of opening its at the right height.
Opening complete
The claw mounting boss (between the two fins) that has to be ground down even with top of coupler opening, I used a Dremel with milling bit. also I just eye balled it.
The Kadee, trim the ears off