I vaguely remember reading something a long time ago to help identify a gm fender vs an aftermarket one when no body part sticker was present.
I think it may have been some particular stamping?
This is for 1973 - 80 years.
I located a pair of fenders nearby, but neither have stickers and one was painted. I wouldve preferred nos, but, begets can't be choosers. What I care most about is GM metal.