Good luck actually finding that bushing. It would be easier to replace the pump.
Yes, replace the torque converter; I have not found anyone to rebuild them, however you can buy rebuilt units, and swap yours for a core.
Florida Torque Converters and
Precision of NH has them, but Precision only sells through their dealers (large pain). I bought mine from FTC. Rebuilding the torque converter requires cutting it apart; they are not designed to be "user serviceable".
If you didn't experience any operational problems, replacing the failed parts is probably all you need to do. If you have the transmission down already, clean the valve body, accumulator pistons and pan thoroughly with kerosene; resist the temptation to turn the case over on its side until you've removed the valve body and drained the case.
Once you remove the valve body, you'll be able to assess the condition of the clutches. If they look OK, you can test the pistons easily. All the information you need is in the unit repair manual, in the 80 series section of the Resources section.
The FSM procedure to remove the pump requires a puller, which you won't find, but there are two threaded holes in the face of the pump you can use as jackscrew points. IIRC, you'll need screws at least 60-mm long. The pump seal face is only about 6-8-mm long, but you have to reach the basket below the pump to push it out. Just be sure to run them in simultaneously, or you'll damage the pump seal bore in the case. If you do that, the case is unusable. It's best to do this with the case standing on its tail. You can use a milk crate with a hole in the bottom.
Standing the case on its tail will also allow you to easily inspect the clutches and check the piston operation. All you're looking for is motion. It will not be possible to verify exactly how much travel each piston has without tearing the transmission apart, but you can gauge close enough for diagnosis with a 6-inch steel scale.
I would be concerned more with cleaning the cooling system. The transmission is designed to reject trash into the pan, however the torque converter and cooling system traps it. There is no way, without a torque converter shop, to thoroughly clean it, but you can, and should, flush the cooling system. You'll need a drill- or hand-operated pump, a bottle of kerosene and an empty container to catch the trash. Connect the pump and fresh kerosene to the cooler outlet line from the transmission, and run all the old ATF out. Once clean kerosene is flowing out of the inlet tube, pump new ATF into the system, using the same method. If you fail to do this, any transmission cleaning you do will be a waste of time, since the pump will recirculate all the contaminated fluid from the lines, radiator and cooler back into the transmission. You can flush the fluid in either direction; a case can be made for backflushing, but IMO any flushing is better than no flushing.
