I ordered a lineset ticket for the VIN on Peer Pressure a month ago or so, and it came in this afternoon. I always figured the plate was not original to the body, because it’s screwed in with sheet metal screws, but I was never really sure. From what it says, the original shell was built on August 18, 1975, in Kansas City for Bob Post Chrysler Plymouth in Aurora, Colorado. It was painted Solar Yellow, Code 4410 (a 1976 color), and it had a 304 V-8 with an automatic transmission.
My body shell was originally painted Gold Poly, a 1975 color, and as mentioned before, is not original to the frame. This basically just confirms it. My only shot at identifying it now is finding the VIN chalked on the body somewhere.