Watch List notes:

British Coins, George III, proof farthing, 1806, K on truncation, date double-struck, laur. bust r., rev. Britannia std. l., holding trident and olive branch (S.3782; P.1386), about mint state
An extremely interesting coin, with a double-struck date reading 11880066. The portrait is the one used on the 1806 Irish farthings.
Estimate: (400-500 GBP)