I just bought a Sabre 28, 1975, which I am going over with a fine tooth comb. I noticed that the Ice Chest/Box in the galley was missing a drain tube. I am going to add one and route it into the bilge. Th old pump is frozen. I notice that the 5/8" hose bib for draining the box has black all around it for an area of about 3" inches in diameter. This is found on the outside of the box on the insulation. Is this from years of mold? Could it be from a leaky seal? Steve