I've been to many a car show where there are huge arguments about whether this hose was routed over or under that hose from the factory. Originality, to those guys, means "as it left the showroom floor." Personally, I just want to ride a nice, interesting bike that didn't cost me $1000. It turns out it's unbelieveably easy to do. I don't have any problem with someone who wants to make any kind of modification to an older bike for the sake of riding it unless that bike is particularly rare or in unusually good condition.

To use your Vette example, no one cares if you take a 1973 Vette with 150,000 miles on it, tub it out for some big tires and throw a blown big-block in it. Everyone cares if you want to do the same thing to a nice, stock '63.