Thank you Jeff. I had the rear fender extensions off the other day and saw the primer. Red oxide primer is what I had heard was the original assembly line color and what I expected to see. Another not seen before curiosity was these small letter/number codes for the rear taillight panel. Actually I don't know what that piece is called ? Brian
Appears that sometimes not allot of gray was applied everywhere and other times a light coat over the red oxide produced an odd pinkish final look
You'll (or should) find the same light grey primer as the top coat, if you remove your rear valance, along the bottom 3/8" or so of the taillight panel where the valance created a shadow.
Haven't noticed the stampings in that area - not sure how long they (stamping plant) did that - now I'm going to have to go through a bunch of pictures again