Hi Em,
I agree with what member freebird has suggested and as it's enamel paint without a hardener added it will stay soft for quite some time.
Rushing into it will spoil all your hard work that you've done and as you've probably guessed by now that I've very much supported everything you've done on this amazing rebuild and you wouldn't want to trash it at the eleventh hour.
May I suggest that you put all the Hammertone enamel painted parts outside in the sun for a few days, this will speed up the curring process, especially with the metal heating up and cooling down day in day out.
As far as the bearing is concerned I totally agree with you that it should be a self aligning unit but if I recall correctly Rover in their wisdom decided that a standard bearing was good enough due to cost cutting (I don't agree). I gather you may still have vto original unit that you removed and on that it should have the bearing number on it. You'll probably have to look with a magnifying glass, well I'd have to anyway. Check out "CBC Bearings" as they'd have it. I know it's still available.
BTW since you sneaked a 20 inch machine in I thought I'd tell what I accidentally picked up today, yes accidentally, a 20 inch Solid Deck (Series 1) machine today complete with it's original HK-30 Kirby still installed and all its original parts. It runs but it leaks fuel terribly from the trickler that's on the underside of the fuel bowl,

. It also has a cracked bearing carrier on the drivetrain side (RH) and that's going to be a hard find as the carrier in the early 20 inch machines are larger than the normal 14 inch and 17 inch machines. Yes it can be substituted for one of the smaller types and thus change the bearing over to an RSL5, but I prefer to keep things with the original specs. It's gonna be a long hard find. Yes I've found a couple of lefties already but no Right handers. Bugger !
Anyway, Keep up the good work.
Cheers,
BB.