"This guy may be a decent fella'... I don't know".
Yes you do! Don't waste any more time on him. Check with a lawyer but I think you're entitled to keep the deposit after so many days/months. Even if you aren't, let him get a hold of you and sue you if he feels cheated. You could counter that is was a breach of contract and/or charge him storage on top of the rest of the money for the tractor. In the mean time relist the tractor and don't worry about him at all. There's a reason he's not contacting you but that's his problem, not yours. I'm guessing he thinks you want the the rest of the money and he doesn't have it. You didn't have a deal with the woman, so stop calling her. He's got your messages and is avoiding you. Why should you care, you've got a $1000 and still have the tractor. Dave