[squirrel_hunter]

To answer the questions and hopefully assist:

I cleaned the shaft by wiping down, no additional solvents. Can't feel anything on the shaft, but that's no guarantee.

I didn't use RRG, just liberal application of new engine oil to assist installation. That is all over the seal, the o-ring and the shaft where there is contact. Once installed any excess was wiped off.

I fitted the new seal by pushing it in then using the old seal reversed so I have a flat surface touching a flat surface with a rather large deep impact socket so it clears the shaft but connects with the seal tapped it into place until the note changed. The o-ring in the spacer was an easy fit. The spacer then was pushed onto the shaft and then again using a deep socket tapped into place. I don't think the seal is out of square in the casing, I've not used calipers to measure just visually and by feel, but it looks fine. But then there is something wrong for sure.

As for the parts I'm using Suzuki OEM. Not got the exact part numbers from the packet as the bins have been collected, however a quick comparison shows the oil seal (09283-36003-000) fits 99-14, the o-ring (09280-24010-000) fits 99-14 and the spacer (27531-19F00-000, though replaced by 27531-19F01) fits 99-14 using the original and superseded numbers. I did visually check the old and new spacer and they appeared the same, but do still have the old one should a comparison be required.