It's cheap, it's easy - go for it. If it lasts two weeks, then so be
it, but at least we'll have some form of quantitative data on the topic
in this newsgroup.

You could build a free standing bearing structure which the prop shaft
bears against (laterally) and couple it to the motor - maybe with a
flexible drive. Or a similar arrangement with the chain drive
preserved (covered of course). There's always the pump route - but not
exactly cheap if you have to go with new parts.