Watch List notes:

WINDSOR. Elizabeth II. 1952-present. NI Trial Die Strike (25mm, 5.12 g, 12h). London mint. Dated 1957. Britannia seated slightly right, striking coins; three coins on ground before her; to right, dolphin upward / ROYAL MINT ~ TRIAL DIE ~, hexagram; 1957 (date) in center. Cf. DNW 135, lot 844 (for type). Iridescent toning, minor deposits, crimping to edge. Near EF.