Musos stick together! I remember the time someone nicked Alan Bell's concertina: it was reported on here, and the thief tried to sell it to one of the Hobgoblin music shops: what yer tea-leaf didn't know was that all concertinas have serial numbers (do Ibanez guitars?) and the guy at Hobgoblin was aware of the loss and checked the serial number of said concertina offered for sale - tea-leaf duly nicked!