Have arrived at a satisfactory resolution. Will post a more complete paper on John Sims' site. Takeaways:
Adjustment is a combination of front shims and adjuster screw adjustment. My previous too-loose shims gave too much play in the wheel, as well as tightness at certain spots.
The used bearings, while looking OK, sounded noisy so I bit the bullet and replaced the bearings and cup races (from Moss).
I used a digital caliper to measure the protrusion of the front bearing cup, then added shims to about .005" more than that. An absolute minimum of play here - like the front wheel bearings. The DWR worm had a slight high spot part way between center and left lock so I adjusted to almost zero play at that point.
I also added a bearing centering collar to the shaft, behind the rear bearing race. This prevents the rear bearing from getting hung up at an angle (which destroyed my original steering). It was made from a piece of 1" electrical conduit squished down to be a light press fit on the column. It does the job without rubbing the inside of the column tube.
I measured the stock and DWR worms by removing the belleville washers and letting the peg ride in the worm by gravity only - with the box clean except for light oiling of the parts. See pix below. The stock worm, zeroed at the center high spot, varied about .013" looser at either end.
I installed 00 grease (same grade as Penrite - available on Amazon).
After carefully adjusting to almost zero play at the steering arm at the high spot, 5/8" of play at the steering wheel was achieved.
After this process, I believe the weight of 0 or 00 grease is unimportant. Numbers of belleville washers didn't alter the setting, so I stuck to 6 per the Moss catalog.
Arm locked for checking play at steering wheel.