I'm rebuilding the engine in my '57 Belvedere. The transmission works fine, but as long as it's out, I'd like to replace seals/gaskets, etc. (It's a 3 speed manual.) Does anyone know a source for these parts? Bernbaum lists parts through '56 only. NAPA lists a rear seal and a couple of bearings. It would be nice to buy a seal/gasket kit if possible. Thanks!