Rich,
You bring up a few interesting stories. First, any car restored has new parts or paint so I believe the restoration is up to the buyer if he feels that it is worth it. Not disclosing what was done in the restoration is fraud in my mind. Not so much rebodying, but I am NOT for rebodying cars.
My second point . . . The 2nd prototype BlackBird we built was bought by a 20 year old kid (by his parents) and 5 days later he turned 21 and at midnight, he and 3 other friends decided to go get their first legal drink (although they were already drinking). The police report said that they left two 180 foot blackmarks from the apartment entrance and went through an intersection at 115 mph and got the car airborn and lost it as the back end came around after the intersection. The car slid into the median and crushed the right side wheels and rocker and broke the passengers legs and then slid around and went through the other lanes and hit the left side front wheel and crushed it and then ended up with a tree 12 inches into the rear quarter in front of the rear wheel. The motor was 6 inches over to the left and the tranny was ripped off the car. Fortunately, they all lived, but the car with only 505 miles on it didn't. It was shipped to a salvage yard in GA and then another, and then another. About 10 months later I got a call from a guy in KY asking if we know about a wrecked black trans am in a salvage yard up there ?? He said it had a silver dash and a brass plate in the door jamb and thought it might be something unique and rare. I asked for the plate info and sure enough it was THE original car. He said that he was going to buy it and wanted me to turn it into a BlackBird again (
http://www.gmmginc.net/html/blackbird.html ). He said that he had a good body and that he would transfer the tags and wanted the stuff to restore it as the 2nd Blackbird prototype. I told him that the only way I would do it was if he fixed the body, no matter the cost, and sent it back down to us after it was restored as a 2001 Trans Am / WS6. He did and then sent it back to our shop (GMMG, Inc) and we then restored it with the BlackBird package. The car wasn't perfect but it was the original car.
My next story is almost to the tee to your hypothetical ZL1 disaster. In 1997 we at SLP built 100 LT4 Corvette engined SS Camaros and they sold new for just over $40,000.00. One, and I can't remember the number, was stored in the owners warehouse when a guy was driving a 15,000 pound fork lift on the second floor. I guess the second floor wasn't strong enough to hold it and the fork lift fell through the second floor . . . square on top of the LT4 SS Camaro, which had like 100 miles on it. I saw pictures of it and it landed on the top and crushed it flat on the floor, from the steering wheel back. The front end wasn't badly damaged but the tranny back was flat. NO possible chance of restoring that car. I know a few guys here at the SYC own one of those 100 cars.