fresh 904 rebuild, not shifting at all

Did you have ANY trouble getting the trans to bolt to the engine? It should have mated right up and the converter should have spun freely with about 3/8" of space away from the flex plate. If you had to "draw it in" with the bolts the converter wasn't seated all the way and you broke the drive dogs off the pump gear. It's easy to do, I learned this the hard way.

Take a cooler line loose, start the engine and shift to neutral. You'll know real quick if the pump is running.