I think I'll shop eBay for a submersible three phase pump motor. Bruce's
suggestion would have no noise at all.

You need the volute and prop to fit BEFORE you buy the motor, so you
know which motor you need - unless you want to mill it from scratch.

And it's probably still going to be 1/2 HP just a different (and
much quieter) form factor.

I guess I'm lucky. I know a machinist that can make ANYTHING adapt. I
cruised eBay today, not a single offer. I may have to look for this motor as
a repair part.

karl