Marginal? Wow! Think I'd argue that point with the doors - the door/sill depth and continuous join of the body is a massive part of the look of the original inspiration.
Really interesting to see how a pro (as in do it for a living) body shop person goes about it - all the changes really enhance it. Totally with you on the rear window it so needed to wrap into the rear butresses.
The 250 hot rod is also an excellent choice to emulate and I'm with you on the deeper red.
Without trying to upset anyone else, it looks (with all the mods and graft put in) like this one will be the benchmark for the coupe kit.
Only thing I'd change is going for wires (even though i now know what a complete PITA they are to keep clean!) but the beamer steels do look great as "premiered" on Bobs coupe