F1 show cars are often built from parts which have been found to be out of tolerance and from damaged monocoques which can’t easily or safely be rebuilt to race again BUT there still shouldn’t be two cars sharing the same chassis number.
I believe there is a Ford GT40 which has been resurrected comparatively recently that burnt to the ground at Nurburgring in the mid 1960’s. Everyone in historic racing circles knows the provenance of the car so it doesn’t matter but it does show that it isn’t just aviation where rebuilds have, on occassions, contained little but the constructors plate.
It is just inevitable that anything which gets used will eventually get damaged and at the same time parts wear out so replacing parts and carrying out major repairs/rebuilds is something which can’t be avoided.