British Numismatic Trade Association, Britannia Silver Proof Medal, Coinex 1987. Obv: Britannia seated on a rock with trident. Rev: 2 portraits of Queen Victoria, in Young head and Jubilee Head versions, within two facing cartouches below a crowned VR cypher. 162.2700 g, .9250 Silver, 5.0000 Oz. ASW. 65mm. Mintage: 500 units. PROOF. Serial Number for this example: 031.