One I remeber involved a 5 string banjo. One of the organisers of the North Wales (Conwy) Blue Grass Festival had his Grover stolen during the event. It turned up at a pawn shop or perhaps a second hand shop in Liverpool a few weeks later, I believe for £100 - It would have been quite a buy for somebody!I think I would always be suspicious if I saw something of that obvious quality going so cheaply and I guess many shops are careful - I had a friend with a music shop who certainly checked up if he thought someone could be trying to pass on stolen property.
In the case I mentioned, the person had a number of contacts all round the country and there were lots of people keeping an eye out for what is not the most common of instruments. As I remember, it was a friend of his that saw it and took action immediately.
Jon