Let's get away from the Cobra for a second as it's clouding the truth.
My friends 1967 Corvette Roadster 427 Tripower has been modified. Flared fenders, all aluminum engine, Different wheels, 5-speed. The car looks beautiful and goes too. But...bring it to an auction and it won't command the money as if it were completely stock from the factory, ---BUT it is considered an original by the VIN and paperwork. The purest would not want his corvette to be parked next to THEM in the stock section of a car show though
I hope I did not cross the line here
Lou