The bearings were actually available from Infiniti separately back in the late 90s. They came in really old looking boxes wrapped in oily paper with Japanese writing on it. I rebuilt the alternator on my first Q with new bearings and the diode board (can't remember the correct name at the moment) only to have a stator fail about a year later - causing me to just get a remanufactured unit. The brushes had tons of life left with a little over 100K in service.
I think I'd just toss it in a corner, so that if the economic apocalypse comes you might get lucky and be able to cobble one good one together out of two or three if they failed differently.
Heath