And here's the bad pump, completely off.
I removed the fan and the shrowd to get access, and also loosened the power steering pump bolts to loosen the tension of belt to get the vacuum pump up and around the belt without damaging the radiator.

I'm not looking forward to tightening up the power steering belt when i close this up. It was not behaving that nicely even with all three bolts loosened. I can tell that step has my number.

After removing the pump, i tried unscrewing a couple of the flathead screws. Man those are on super tight.

Is that the section i should be opening up to potentially replace some sort of valve inside?

For now I might just avoid that whole headache and pull over the pump from other car and work on refurbing this pump later.