Somewhere we might have the old prop off a 1972 Johnsorude 25 where the rubber bushing let go and so it won't transmit more than about 8 Hp before the hub starts to move independently of the blades. To the untrained eye it looks fine.....
If you're on Arran, chances are I'll be out or near the Clyde sometime so could just pass it across or swap for a couple of bottles of that Gold your local brewerey produces
. Just need to find out where it went first.... Are you in a huge rush?