Like Randy said, the new paint and body putty can be removed, but any grinding and porcelain removal that was done to facilitate this process can never be undone!
no body putty, grinding or porcelain removal or clear coat - can be put back with a little lacquer thinner - your not defacing it where the next caretaker can make a decision on the before look or after look- this one not perfect but too the human eye (not camera) looks much better..
I agree with Kevin with altering a sign with body putty, grinding clear coating the sign, it isn't original no more & too me is the same as a repo & cannot be put back..
my 2¢ but may be only worth 1. .. ...