Mo,
Tell your Dad THANKS!
One thing leaves me a little confused. I've seen many original firewalls that clearly show the crayoned paint or trim codes (sometimes option codes). I wonder if that's just because the paint didn't stick to the crayon ("grease marker"), and overtime, the paint just disappeared from the moisture and elements. When I've seen those on an original car, I sure didn't wipe them off to see if there was paint or bare metal under them. I left them alone!
It sounds like you're saying that back when the whole car was painted one color, including the firewall, the firewall was skipped until after the bake oven, then it was shot. I wonder why they wouldn't have shot the whole thing at the same time while the "gun was in hand".
I'll post a couple more questions in a bit, if that's ok. Like Tom C., I could spend hours with your Dad and not run out of questions. The history and the truth are SOOOO important.
Verne.