Do they not make rear quarter repair panels or the 69? I'm no stranger to metal work, as you can see by the shaved tailgate, gas door and 4x4 widened rear wells I did on my truck.
Paint will remain yellow, however probably with some orange pearl.
Lots of places sell the sections which are in high demand for rust repair, but know of noone who has the parts you would need to change to the smaller taillights, I think these would end up needing to be cut from a donor hulk.
I have a pretty rust free 68 in our back yard, but you are too far away to pick it up. You will need to buy a complete car to get all the parts I would imagine.
Embrace your fat-chick-inish after all the worst bumper/lights offered on a ghia is still folds better than the rest of the coach built cars ever offered.
Yeah some may call it overkill, but you can't have too much overkill.
build your own replacement panels and graft in the tall skinny caddy tail lights--at least that's what I've considered doing if I ever get a big tail light ghia. . .