This is probably repetive, but I think it depends on what you have to begin with. If you have a nice solid original, I think it is a shame to cut it up. I always think about something some once said to me: "No matter what it is, we have only a short term lease on it." Nice old originals are hard to find. On the other hand, if it is something that has been neglected badly, and you are saving it from the crusher, have at it. Do your thing.

Personally I'm not into the 100% percent original restoration deal. If I can get one back to looking like a fairly well maintained vehicle would have looked when they were in general use, I'm happy. But then, to each his own way of doing things... Allen