The secondary RA-washer has a problem, but not with itself...
Incidentally, that is not a gouge into the washer's surface, rather only an abrasion, a "polishing" of the surface.
No, the issue is with that part of the axis instead...
Note the very narrow ledge where the washer is expected to rest. SYNTA!
The surrounding area can be filled with an aluminum washer, then the bronze washer on top of that, and for extra support. However, I feel it would need to be at the exact height of the ledge, but perhaps not. In any event, I didn't bother. I can always return to that, if there's ever a problem.
It is for that very issue that the inner-diameter of the washer must be roughly determined, then carefully enlarged to where it
just slips over the worm-gear's drum...
I wanted that washer resting over as much of that narrow width as is practically possible. It is quite snug, but will rotate freely if required.
I could not saw out any of these washers, precisely, and expect them to fit without adjusting, perhaps not even with a lathe. That's not going to happen, not with my dubious, suspect set of ISO 9001 "standards".
But where are the smaller washers, and for the secondary ball-bearing ring? They were cut out of the same sheet of bronze. Ah, here they are...
I made two shims, of the thinner, 0.008" bronze...
...and for the inner-diameter of the ball-bearing ring, as I don't want the inner edge of the steel ring rubbing against the threaded, aluminum portion of the RA-shaft that it will surround. In addition, I don't want the ring to oscillate as it rotates. That's called having two birds in the hand, instead of just one, and with the other in the bush.
The two washers for the secondary ball-bearing ring differed from one another somewhat, and per these measurements...
At left, the inner-diameter of the lowermost washer is about 1mm larger than that of the uppermost. The red line denotes the division of the inner and outer portions of the RA-shaft. At right, the lowermost must be able to drop into the well, as indicated. The uppermost might need to as well, therefore it's best to simply have both with that ability.