I'd say that a new vinyl roof and fixing what's under it are in order--period. The rh lwr corner looks similar to what my "43" looked like, when the vinyl covering was still on it. When the vinyl was removed, not much metal left. Like anything that's still there would crumple if you ever tried to remove that lower section of the rear window molding. So, my suspicion is that there's more holes hiding under the holes in the vinyl. Which also means the trunk pan "reservoirs" on each side probably have some issues, too.
The mentioned quarter panel/roof joints being "a place" is very accurate. On my DH43N0D, even when it was newer, didn't have smooth sections there. When the vinyl was gone, not even full coverage of lead filler at those joints! On either side. Just part of the game back then, it now appears.
To it's credit, whatever that might mean, it was a pretty nice car before it was parked. It can be, again, too. Nice interior, but what about the instrument panel pad?
A stroker LA could replace the 318, but better check those rust issues first.
Enjoy!
I think the folks at Chrysler preferred putting a vinyl top on one for no other reason than it meant they didn’t have to finish the roof. I don’t think I have seen many that you could tell exactly where the roof/quarter panel met, even on the best examples. These cars were never built to last 50 years and not show signs of aging.
I don’t have a dog in this race, but I have seen the car first hand. I didn’t roll around on the ground or go over it with a microscope. But, I saw no obvious signs of shoddy repairs or severe rust issues that were beyond repair.
How about those quarters? Nobody commented on those. Did you ever see quarters rusted out so bad that you could throw a cat through one side and out the other?