Thanks to Bill and Christopher.
I took the vacuum pump apart. Removed the motor, cover, and took the pump body apart from housing and removed one end of the body, exposing the rotary vane. As an aside, it had quite a bit of sludge in the pan. I realized that it was slightly rusted, not completely but just a little bit. After the disassembly, I had better access to the shaft. A generous use of a big wrench made the pump unstuck. I washed the cover to get rid of sludge, reassembled and refilled the pump.
The good news is that it pulls vacuum, not sure how deep but it pulls quite strongly on my finger when I try to close the vacuum opening with a finger. I do have a vacuum gauge (from an old broken pump), but the gauge is 1/4" NPT and the pump has a flare fitting. Maybe I will visit Ace Hardware or HD tomorrow for a fitting to put the gauge on.
The question I have is this. When the pump starts pulling a real vacuum, but before it reaches equilibrium, it makes a gurgling sound. Also, it seems that the oil became bubbly with a lot of little bubbles. I see them in the access window.
Is that normal? I am suspecting that perhaps one of the vanes (I think that they are called vanes, the little rectangular thingys that go in and out of the rotor to maintain vacuum) is stuck and does not move back and forth. Could that account for the gurgling sound?