Just to clarify the door skin thing for those that may not be familiar with it. You still want to "fold" the edges over the inner shell flange even though you've bonded the face. In other words, a normal skin replacement except for adhesive instead of welding.

Sounds like you have the rest of the idea. You could still bond the quarters on, just weld the mating seam to the sail. (Sorry if that wasn't clear in my original post.) You could lead over TIG, it doesn't know the difference, but, unless you're going for bragging rights, polyester fill would work just as well.

I know what you mean about not finding someone to do it your way. Twenty five years ago I tackled my first metal straightening for the same reason. I had a '51 Hornet that some kids had used the roof for a trampoline when it was laying in a field. The rest of the car was so sweet, I had to save it. Great learning experience hammer and dollying all those little ripples.