I'm just curious: did he provide you with any reason for cancelling the project? Was any communication between the two of you after the project was cancelled? I don't blame you for being angry, but that's the chance we take when doing private projects for commission. Perhaps you can make this part of your model portfolio and sell it. I know you do mostly private work, but you might end up making more money with this over time, in the long run.
Good luck going forward.