I sanded the back side with a DA sander and 320 grit, then I used a tiny flat screwdriver and some acetone to get the old paint out of the back side of the lettering, since it is recessed into the back. Once it was clean I painted the back side with three coats of silver, then sanded off the back again with the DA sander. Since the letters are recessed they stayed silver. At that point I just painted the back side with three coats of semi-flat black and let it dry, then cleaned off the overspray on the fronts with more acetone and waxed them a bit. I used some mastic to re-attach them. They are not perfect but they look alot better than the nasty ones we all have.
