That is a really touchy subject. There is a thread on Moparts right now dealing with this same issue. Some say if the car is rusted out and replaced with all new panels, or using another car to replace everything is a rebody. As long as the motor is original, even with new parts, I wouldn't think that there would be a problem. But one would be wise to disclose all facts. Even if the motor was a factory replacement I wouldn't think that there would be a problem. Some people are sticklers for details, though. As far as body replacement panels, parts and all the millions of little details - well, that would be up to you, as a buyer. New carpet? Not original. New seat skins? not original. How far are you willing to take it? I would just drive it and enjoy it. If you are spending the insane money for "all original" then you are not going to be driving it and enjoying it anyway. It will be locked in a vault. Hopefully not the one they dug that old car out of a few years back! Chebby people have it SO easy. No one cares what theirs is, as there were a gallzillion of each and every one of them made. (ok - SOME might care a little bit) (I've got just one of 94,000 Nova SS with this paint scheme! lol) Many shops back in the day did whatever they could just to keep an old heap going. ie, rebody. You will never be able to track that stuff down and make it factory new without buildsheets, fendertags and someone that drove it around the lot a few times. You aren't going to live forever. So don't spend insane money, and just enjoy it. Let the heirs fight over it when you are gone. You will get the last laugh! Otherwise, Steve Juliano might be able to help you out. He has some nice rare stuff. Umm... Why do you ask? lol!