If it was his knife to begin with and you rehandled it, I think you have what is called a mechanic's lein on it. I'm no lawyer but I think this lasts for 30 days after you notify the customer and if they don't pay, you own it. You might want to go to your county court house and read the laws that cover your state.
Of course this only covers the legal part of it, not the customer service and good will part. Personally, I would put it away and wait till I heard from the guy again. If you don't have his address or phone number, you might be able to find it online and write him a letter or call em.
Take care!! Michael
Always think of your fellow knife makers as partners in the search for the perfect blade, not as people trying to compete with you and your work!
I would give it time. People skip town all the time unexpectedly or things comes up. Someone out of state is never going to sue you for work you did that went unpayed. You have the knife as collateral, and there aren't too many lawyers who will cross state lines over a few hundred bucks. Although, you probably want the transaction to go through smoothly, not get a new knife! Give the guy the benefit of the doubt and see how it plays out...
I agree with giving it time. Our human nature tends to fill voids with negative material. Things happen,not in our control sometimes...he may be out of town or in the middle of a family crisis. I would give benefit of resonable time. Deals done with an internet "handshake" are always vulnerable. We require a credit card number or 50% deposit before starting custom milling work. Not so much to protect the time and material investment, but to establish the level of "seriousness" and "commitment" of the client.
I recently sent three unanswered emails to a knife show promoter. I really wanted to do this show, but not getting the "courtesy" of a response if only...."Sorry, sold out", I was prepared to fire off an email saying "Thanks, but no thanks", if this is your public relations. Finally, got a reply and the promoter had been out of town and "Yes, please do our show". I felt pretty small.