Seeking advice - oil pump/timing cover damage?

[Pathogen]

Problem: Low to No oil pressure at idle after the car reaches operating temperature.

Possibilities:
A) Oil pump bad, replace pump
B) Spun bearing, ... generally bad stuff

-- Tore into the motor yesterday, but my new pump never showed up, so I couldn't do any test fitting (etc). I'm requesting some advice based on the information below.

The current pump does not spin smoothly in the timing cover, but the gears do not appear to be terribly worn. After removing the pump from the cover, I discovered groves in the cover that correspond to grooves in the outer gear.

Right now I'm riding the fence on replacing this $180 timing cover because of the grooves. Is it possible to sleeve a timing cover and would it be worth it rather than replacing the stupid thing?

Secondly, does this sound like it could be the source of my oil pressure problem, or am I still looking at a possible motor rebuild?

[AZ3.8Camaro]

The current pump should spin in the cover. I would say its a definate place to start.

With something as important as oil, I would replace the cover and the pump.

Where exactly are the grooves?

[Pathogen]

In on the spin surface ... I guess that's what it would be called. They're in the cover and the ring gear. Not where the teeth of the gears meet.

I'm not sure if they're really grooves, but they're ridges like something got in there and just ripped the piece up pretty good.