Yeah, I agree, it sounds like the only option left may be to try a different known good pump.
Or another option that could be easier if another known good pump is not easily found: If you have a Bosch fuel system rebuilder shop that is operating near you, then you might also be able to bring them the injection pump and have them run it on their test bench. If there is any issue with the pump they would be able to see it when they run their tests, and then probably would be able to rebuild the pump and fix whatever might be wrong. These old VE pumps are still used in many pieces of equipment and vehicles all over the world so any good diesel injection shop with the Bosch sign out front should be experienced and certified to work on them.
One other test that could be worth a try: if you are able to get an infrared thermometer, you could check the temperature of the exhaust manifold at the port for each cylinder. If it has a weak/skipping cylinder (due to any issue -- fuel pump or injector, or something in the base engine) then you might be able to see that the problem cylinder is running cooler than the others.
The compression readings look nice and the engine sounds good in the video other than the driveability problem.... so it hopefully should be a very nice runner once this issue is figured out.
