Watch List notes:

COINS, EUROPEAN TERRITORIES, ISLE OF MAN George III (1760-1820), Bronzed-copper Proof Penny, 1798, Soho mint, laureate head right, rev Triune (Pr 18A; S 7415; KM 11a). Mint state.
ex Dr R Caine collection of the Isle of Man, Spink Auction 145, 14 July 2000, lot 2739
ex Pridmore collection, Glendinings, 22 September 1981, lot 486 (part), with ticket

Estimate: £300-400