I just recently sold a presumably OEM headlight bezel for 1970-72 Nova. Because it was packaged in an old GM box, I sold it under the presumption that it MAY be OEM, but I wasn't sure. After having a discussion with some interested parties, we came to the conclusion that the repops don't usually have a part # stamped on the back, and the OEMs do. When it includes a part #, it can be checked with a GM parts book. But, then again, I've seen many so-called NOS parts with part numbers that are definitely repops, and sold as OEM parts. OEM parts bring big money usually. I sold the bezel I had for $82.00, but still don't know for sure if it was OEM. Even the repops are going for more than that! It boils down to, "Buyer Beware!"