Art, architecture, and classic cars should be restored, just about everything else deserves rebuilding.
What I mean to say is that if the Imperial Palace were damaged, you would want to restore it exactly as it was. If the you accidentally ripped Van Gogh's "Sunflowers," you would try to restore every thread.
However, if you broke your tape recorder, crashed your airplane, or sank your yacht, you would want to improve upon the loss.