"Too big" is usually not a problem. Most of the custom parts I use in my gunsmithing business come to me just a bit oversize- - - -that's where the "smith" part comes in. Anybody can install a drop-in part. A mechanic, as opposed to a parts-swapper, should be able to do a reasonable amount of fitting, especially if he's dealing with a non-stock part like a billet assewmbly. It could have been too small and left an unsightly gap, and you would have a legitimate reason to complain!
Jerry
