I totally hate crap like this, especially when the Issue started here. I'm sorry about the problems this has caused.
Not that it helps now, but I would have gotten the Deposit in Cash, given the Buyer a written statement that the $100 was non-refundable, (Since you were now telling other people that the Top was Sold) and waited on him to come up with the rest of the $$.
Unfortunatley, you're kinda screwed now. I just had a problem with my Bank involving a Late Fee. I polietly told them my situation and asked them if they could reverse the Late Fee. They did without a problem. See them in person, not by Phone. Good luck!
I wouldn't tell his name, but keep trying to work it out between you two. Hopefully he will be willing to make things right between you guys.
I hope this isn't the case for you, but sometimes you just have to chalk it up as a lesson learned. Good luck!!
Heres a little story for ya-
When I was selling my YJ, I had a buyer that wanted it badly. He test drove it 3 times, and kept talking about how he wanted to buy it. He wanted me to tell other intrested people it wasn't for sale anymore. I told him that for a $500 Non-refundable deposit I could do that. Untill then, Money talks and BS Walks. He said he had the $$, but after our discussion about the Deposit I never saw him again. I sold the Jeep a week later to someone else.