Manual trans's? Find the cheapest trans for one of your cars that you can, and sit down with the shop manual in hand, and fool with it. If you had a sprite trannie say, you can remove the side cover, and shift it through the gears, and see what happens. After you understand how it works as a unit, disassemble it and see how that goes. If it does not have to be an "in service" unit, you can re use the old bearings, rollers and so on. I like doing trans work. It is like a 3D jigsaw puzzle, and will (almost) always only go back together one way. Pay attention to the orientation of the parts as it comes apart (I use sharpies to mark things I might forget...) I find having a parts book helps as much as the shop manual sometimes so you don't miss spacers and the like.