I should have reversed the flange bearings by now to avoid having any bare shaft above the bearing. The minimum amount of cantilevering is desirable to avoid any chance of shaft flexure.
A thin, steel, expansion ring is supplied with these bushes but it was slightly too large in diameter to fit between the flanges of the channel section saddle. I had already had to grind small flats on the Tollok bush to fit the largest flange into the channel. Cutting away the light alloy saddle, to allow the bush to fit inside, would probably have weakened it. The small flats I ground and filed smooth will not affect the Tollok bush's strength at all.
Having the Tollok bush available has allowed the saddle to be supported with virtually no overhang. Every bit of unnecessary overhang means extra counter-weighting for the OTA. One just has to ensure OTA clearance for the large RA wormwheel.