Sorry Im sure this topic has been covered before but I was unsuccesfull in finding it

I just received my t molding and after test fitting it I noticed its a hair (literally) wider, using 3/4 T molding on 3/4 birtch ply. Is this common, if so do trim off the excess? On my sega made cab the t molding is flush with the side, but doest look like it was trimmed.
Any help/advice would be appreciated
mj147