No matter what hypothetical you can come up with (ZL-1's with a steel beam through the roof and floor, etc.) there will be some guys who cry foul and some guys who commend you for 'saving' a rare car. It's just the nature of how different people value things differently. There will always be people who disdain anything but a virgin car (numbers matching, never raced, never modified, unrestored, etc.) and others who won't care if the engine is a replacement or if the car has been painted the "wrong" color.
Did you see the '67 Shelby sell at Barrett-Jackson for $260,000? The car had a new aluminum 427 engine and had been repainted (restored) in black with white stripes--not the original color. (Mr. Shelby himself apparently signed-off on the new engine as being a 'factory' piece, probably because he sells them for his new Cobras.) That car is "supposed" to be around $60-75K but rolled off the block at just over a quarter-million dollars. There are guys who will say "I wish I could have bought that beauty" and others will say "That buyer is STUPID." Hey, it's all a matter a perspective. There is a LOT of money out there and people seem to be willing to part with vast amounts of it for a car that grabs them. Yes, that makes it harder for those of lesser means to participate in the 'hobby' yet we may benefit when the time comes for us to part with one of our cars.
Who disagrees with this statement: "I want the lowest price when I buy and the highest price when I sell."
Who wouldn't love to score a "shrink-wrapped" ZL-1 that had been sitting in a dealer's attic for 35 years? Of course we'd try to pay as little as possible for it (Shhhh, don't tell anyone!) and then shop it around to see if we can get what--a million dollars for it? Hey, let's take it to Barrett-Jackson! Yeah, that's the ticket! CHA-CHING!
Oh well. As with politics, where you stand depends on where you sit.
Oh, and that heavily critiqued Burnished Brown COPO at B-J? I'd change the color and have a ball with it, but that's just me.
