Stormin Mormon says...

Thanks for the update. I've found that brake cleaner or
carb cleaner works well to remove dried out lube. Zoom
Spout turbine oil works well for oiling. I've heard that
two stroke gas mix oil works well, also. Not the
gasoline mix, just the oil.

Yeah, the problem was just that after 25 years it just had
no effective lube left. One bearing was completely dry. So
I cleaned all the dust and crud out, added a fair amount of
oil, and now it works fine.

By the way, these fans are really nice if you find one
that's still in one piece (the feet tend to break off).
This is the 7-blade original Kool Operator, not the current
5-blade version, which gets bad reviews. The old one's Low
setting is just perfect - moves a moderate amount of air at
very low noise, which is what you want 99% of the time.