Anybody with a lathe and about three brain cells to rub together should be able to adapt a bearing with a slightly larger inside diameter to the spindle. Just machine a sleeve with a flange on it for the spindle nut to tighten against that will center the bearing on the spindle. A first-year machinist's apprentice would be able to turn out something as simple as that in a matter of minutes.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!