I agree with the above, the way it should have been handled, is with some money being held in escrow.
At this point, I would just mow the lawn. TO me, its like separating scrap metal. I figure time is worth $100-$200 an hour, so if I need to spend hours selling cheap parts, scrapping metal, or, doing small claims court to get a couple bucks, not worth the time. Maybe you have more time or its less valuable.
Prinicples, getting even, etc, bah, get over it. Won't be the last time in life it happens.