Proving Pieces, Royal Mint, London, Trial Dies (2), 1927, bronze, edge grained, 25mm, 5.10g/12h (cf. DNW 114, 1591); 1957, nickel, edge plain, 25mm, 5.67g/12h (cf. DNW 114, 1592) [2]. First about very fine and with minor edge flaw, rare, second brilliant mint state £80-100