Any machine shop could make up an adapter for a salvaged motor from scratch. You may be able to start with a shaft adapter from McmasterCarr.
I've done that already and not happy with the results.You don’t need a powered solution at all. Instead, glue a portion of a wide sanding belt to a flat substrate to make a sanding slab, then turn your partial vessel upside-down and move it around by hand. A few swipes will even out high spots quickly.
Tim
HE DOESN'T WANT A LATHE!Think vertical lathe. Build a potters wheel. Small motor to keep weight down, pulleys to step speed down, and a shaft that will accept a chuck.
Or find a cheap used lathe and pull the headstock to create the potters wheel.
It’s no longer a lathe when just the headstock is used and oriented vertically. It’s a potters wheel.HE DOESN'T WANT A LATHE!![]()
Then put a circular platen on a vertical-shaft gear motor similar to my sharpening machine shown here:I've done that already and not happy with the results.