Its going to cost more to "save" this one then it would cost to go a Barren-Jackson or Mecome Auction and buy a rust free restored Cuda convert. I don't see it coming out of any shop for under $200K. The big name shops can easily double that.

My 49 Dodge pickup, at my welding shop, at my shop labor (which was low compared to others in my area) would have been nearly $200k in just labor time, if I did it for you (1 guy, 2080 hours labor time only, 2 guys doubles the labor rate but might cut the time by 25%), plus the parts. That probably isn't anywhere near the quality you are looking for (it is my truck and I am OK with how it came out).

Time is money. Metal replacement takes time, dissembling a car takes time, chasing down parts, reassembling the car takes time, the details that make it look great takes longer!