If all people were honest it would, in fact, be a miracle.
So, if an original ZL1 Camaro is discovered and it needs extensive sheet metal, people will 'stay away from it' or 'it will be worth a ton less money'? That doesn't seem reasonable to me, but, I am not as tuned in to these cars as well as most here. Is it really documented that rare cars (i. e. COPO Camaro's) that are the 'Real Deal' that need sheet metal are not desireable? If a COPO that is all original brings 200G's, one that has a beautiful resto using some donor sheet metal is worth what? Both have the original drive train and are documented.
Over on the dark side (Corvettes) the difference would not be nearly so great.
Regards,
Mark