Watch List notes:

COINS, EUROPEAN TERRITORIES, ISLE OF MAN George III (1760-1820), Copper Proof Halfpenny, 1786, laureate head right, date below, rev Triune, edge grained (Pr 31A; S 7414a; KM 8). Single spot by king's forehead, otherwise mint state with lustrous dark tone.
ex Spink Numismatic Circular, August 2000, item 3346

Estimate: £250-350