To answer a couple of questions.
The FBI has a database where all states must register criminal records. Part of it is stolen property records. When I was an officer we would call in tag numbers for a check.
http://www.fbi.gov/about-us/cjis/ncic
Rosette rivets are legal to possess in some states. In many states possession or manufacture is a felony. That is why the sale is not allowed on this board.
In this case I would recommend seeking legal counsel. In many states the clock on the statute of limitations starts when the crime has been discovered, making it possible to pursue the seller in a civil case and recover at least part of the money. But that depends on many factors.