Ryan,
If that thing runs, I'd say DEAL! That's a good price for what you are getting. If you end up not liking the tractor, you could always sell it and keep the tiller. I checked the pics of your 682 and you have a cast rear. The tiller will mount to it just fine. As far as the PTO killing the motor.... probably has a bearing out of the deck or mule drive. AFTER you buy it, pull the deck drive belt and see if it will engage. Then check the deck out. Don't worry about the motor mounts. There are several options to repair them.
