Originally Posted by JohnDThompson

If it's just corrosion that concerns you, you can get the threads chased to clean them out. If they're cross-threaded or stripped you might have more of a problem. In order of increasing difficulty: There are threadless bottom bracket cartridges from e.g. Edco, Mavic, YST, Velo-Orange, etc. that can install into a stripped shell. Or you can get the shell reamed and tapped to use Italian thread (assuming it isn't already Italian thread; if so a threadless cartridge is in your future). Or you can have a frame builder fill the damaged threads with brass and re-cut fresh threads into the brass.