Any good parts store should be able to get you the seals, and I know for sure that Napa can get the gasket kit (that's where I got mine).
Here's a couple of places that you might also check with;
http://www.drivetrain.com/parts_cat...kits/muncie_3_speed_ld_overhaul_kit.htmlhttp://www.mackstrans.com/MuncieID.htmlYou mention gears, are yours damaged? If so, you might consider hunting another transmission, if only to strip for parts. The SM318 is very common, and can be picked up fairly cheap at the swapmeets. Or better yet, look for the SM319 variant, with has a Borg-Warner overdrive. It's a bolt in swap if you can find either the Truck or the '55-'57 Passenger version. I see them fairly often in the $100-$150 range. Both transmission are very easy to service.
