Ahh, I see the shim your asking about. There shouldn't be any rubber at that point, the only rubber in that mount should be the bushings. As far as the shims go all you have to do is use some sheet metal or steel plate with a couple of holes punched in them if you need to add shims. Any hardware now carrys steel strip ranging from a 1/32" up to 1/4" just whack off what you need with a hack saw and drill the holes, no need to beat your self up trying to find a vendor that has them. They would stiff you on the price any way.
DG


Denny G
Sandwich, IL