@delray Brian, thank you.
I was planning on following your bearing thread suggestion with new ones anyway.
And then I wondered about the possibility of 'reconditioning' the old ones, like you are suggesting, but was uncertain whether that was 'ok'.
I suppose if the ball bearings appear round and in good condition, that there'd be no harm in trying.
Wondering also though if my old bearings are slow speed conveyor bearings like
@cfh was referring to, and better to avoid ?
Anyway, I may try reconditioning one to see how it goes.
Thanks for everyone's help.