Every time this subject is discussed, someone mentions the fact that the recess in the lug may not be round, so the shimmed surface may not be round. My reply is "Well, what am I supposed to do about it?" I think for home made repairs, it should be assumed that both the recess and the pin are "round enough". If we want to make it rounder or better mated, just use a lot of smoke and round files. Or not.