The 5-speed gear cluster is original and probably worn out. I have a newer chain installed that isn't stretched, but the original chain was, so I assume the cluster is shot. I'd like to replace the chain and gears with something new. The wheels and hubs are original.
Can I install a new gear cluster on the original Viscount hub?
On the BB, I think you can get a Phil Woods retrofit that's not cheap, but apparently pretty good. Sheldon Brown has a page or two on that, I think. The stock bearings are off-the-shelf parts, so they're easy to find replacements for. The shaft, on the other hand, is another story.