As far as painting the bell end... Can I also paint the underside of the bell to prevent from rust or it's not recommended due to proper grounding?
Yes! As long as you use the star washers, the ground will be good. I use Rustoleum Appliance Epoxy paint. Made for direct to metal application, no primer. If you apply paint heavily, I would scratch though at the hole to ensure a good ground.
It is probably just me, but I hate to see unfinished bell caps!!!
Cheers,
Geary