I have a beautiful old oak-trimmed, tin-lined, claw foot bathtub that I would like to put in our new renovation. The outside cast iron shell has some pitting and small holes. The tub is water tight, but a rupture in the tin liner would be catastrophic. It seems like there are several options: 1) take the tub apart and line the interior of the cast iron shell with fiberglass and then reassemble it; 2) fill the holes and pits with Bondo or some other filler and then repaint it; or 3) find another tub. I would hate to choose option #3. Any advice on which option to pursue and how I would do it?