I had the exact same issues with my Vermeer. Knock on wood, rebuilding the motor shaft and replacing the hub at the same time seems to have been a permanent fix. Unfortunately I don't have a source for parts. Possibly find a used unit for parts?I am from Michigan. What happened was key in tapered shaft and hub got sheared. I replaced key and it was godd for few months. I carry alot of heavy logs. Then it sheared couple more times as the hub is more than likely honed out larger than shaft. This has ruined the shaft threads. After trying to get thread back professionally, ended up welding hub to shaft . This worked twice. Then shaft broke. I have new hydro motor and shaft on way. So this is where we are. If cant find hub, going to try have one made.
Thank you for you replies. Yes , Im just waiting for new complete motor/shaft to arrive and then will bring old hub to machinist. He will either say yes or no can do. My thinking is also that finn is not the only wheeled mini out there that uses this hub. Just cant find anywhere to cross part #A good machinist should be able to make a new one using the shaft dimensions to get the taper and keyway correct. The other machining of the hub is pretty easy with the part as a go-by. They might even be able to press in a sleeve and then machine the taper and keyway.
Good luck finding a replacement or a good machinist.