I can’t speak to the side trim quality but I know fitment is an issue with aftermarket parts for any of the other trim .....the Horshoe around the rear tail lights on a 63, the import repops don’t even come close to fitting .....but you wouldn’t know that unless you held it up to the car......I couldn’t believe they sold them to me .......I got took!!!!.....I’ve also been told the overseas doorhandles, the chrome starts to bubble immediately........Did you try searching the topic
Look on the back side Bill. Believe the edges are rougher. Specialty Reproductions repo the door and rear quarter clips exactly to GM specs. The repo moldings are too wide to have the clips retain the moldings correctly.
Granted..NOS moldings are basically non-existent now. I'm glad I did cars when NOS was available!!! Don't know of any alternatives...sorry.
Used to be....not sure if it still is....company had 62 Impala side moldings reproduced across the pond.....when shipment arrived and was inspected.....85% WERE THROWN AWAY and the remaining 15% were sold as driver quality.