Watch List notes:

† George III, shilling brockage, 1820, laur. head r., rev. brockage of the obverse (brockage of S.3790), certified and graded by NGC as Mint Error Mint State 61, Brockage on Reverse
Very rare and unusual. The piece seems rather undergraded in the opinion of the current cataloguer.

Estimate: 800 - 1200 GBP