Another thought. Regardless of where and how you end up getting a new tiller one thing I've found that is very worth doing when you mount it to the tiller head is to drill your holes, then remove the tiller, and redrill the holes so they are a little oversized and fill them with epoxy/fillers, let them cure then redrill to fit the tiller head bolts. This creates an epoxy sleeve around the bolts that is waterproof so you keep moisture out of the wood and avoid finding yourself with an unattached, rotten ended tiller in the future.

Tom