i always thought that the metal IS what makes up the car. plus everything else that goes into it. nose/grill, suspension, wheels/tires, seats, wiring, glass, engine/trans/rear, bumpers, exhaust, etc, etc. especially the VIN and Title. parts fail and have to be replaced (on EVERYTHING mechanical), that doesn't mean it no longer the original car.
many people have taken a car and stripped it out and modified it to run oval track. now, is it no longer the car you started with? technically, it is. your just modifying it to your liking. restoration would be this only in the opposite direction. people have been modifying cars to their liking since the beginning of the automobile. chevy owners are probably the biggest offenders of this. how many camaros or chevelles do you see with SS emblems on them that don't belong there. most likely every one.
the bottom like here is, it's gonna matter or not matter to the person who has the briefcase full of money looking to buy that car. everything else being said is just hot air.
the only wrench in the whole thing is................... if the seller is claiming the car IS something it IS NOT. that's fraud.
after all this typing, not sure if i got my point across.............i'm posting it anyway