I feel left out. Guy who bought his 70 model in 78, but the doortrims and handles have never been off since new...
If I was on the forum still I'd claim my RHD-converted 78 was factory since it's been that way for the 20 years I've had it. None seem to have resorted to build diagrams yet. Like Facebook, the stupid topics get replies, the serious ones ignored. I seem to recall my seatbelt post about which way the twist went also went ignored haha. Had to resort to many photos to see if my rewebbed seatbelts were the right way. As it turns out, one way to ID Firebird rear belts to other GM, as they mount up not down, opposite anchor, rambling now...