The whine was still there, and there is a little roughness in the steering at low speeds, so I added a little Lucas power steering stop leak, maybe about 100 mL (30 ounces or so). This almost immediately made the power steering pump MUCH quieter, but the moaning and roughness during low speed steering is still there. It may be overfilled again at this point by 100 mL, so I may have to remove a little.
It's looking more and more like Tech II has the true and ultimate answers, a bad part. If it's still rough and moaning by the summer I'll get an ACDelco reman. I should be able to keep the reserevoir.