Seem to have sorted this out. I put the other BB I have in (thin cup 68-SS spindle with thick cups, along with a spacer on the fixed cup... ebay buying mistake ). I used a set of balls in retainers. Result: no noise

Swapped in the original 68-SS-120 spindle after removing spacer on fixed cup. Result: no noise

Swapped in original fixed cup. Result: no noise

Swapped in original adj. cup. Result: no noise

Two things I noticed were a bit of noise from the workstand on the seatpost, and a bit of what I would term grease noise. The noise I was hearing yesterday sounded like bearing balls hitting each other. I had verified each time that the balls were in properly. I don't see much advantage to going with loose bearings here as you cannot fit an additional bearing in. I guess I'll use Michael Angelo's tip of replacing the balls in the retainer next time I need to do this.

And no problem tacking onto the thread Al; very similar issue. Thanks for all the thoughts!