I spent a bit of time on it today, for info here's a cut through diagram. Note the bronze bearing is incorrectly pointed too, red arrow corrects.
So I confirmed the spindle is snug against the rear bearing. Removed the locking rings slid the bronze bearing back and forward and ensured it was snug against the front spindle taper, then tightened the locking rings. This locked the spindle so backed off until it turned smoothly. I also pumped some oil through to make sure it was well lubricated. However, I think it was OK before as everything is back in exactly the same place.
I had a machine with that kinda bearing.....
I fitted an adjustable oil dripper to it...much better idea.....
Once ur's is adjusted, providing it's OK they hardley ever need to be touched....
but I have seen em all scored up and useless because of lack of oil....
That had crossed my mind as well, will be interested if anyone has had issues and fitted one. The bearing was all smooth and good when I took the spindle out to change the rear bearing but if it keeps wearing I'll take it apart again to check.