I'd say high grades om metalwork, back to the drawing board on the top. That will require a LOT of work and thinking, especially if it is kept functional/folding, and I certainly have no idea how one would engineer that! Perhaps a logical starting point would be to scrutinize some of the huge classics out there with that sort of body.
It's a shame the top was fully finished--it's a discard for sure.
I once saw a Nash, details unknown, with a body like that...it was in a famous huge junkyard full of antique cars in Rhode Island, in the 1960's. Even as a rusted hulk it was a memorable car, still stuck in my mind.