Watch List notes:

(x) William IV (1830-37), Bronzed Proof Penny, 1831, rev. inverted die axis, edge plain, 19.02g (BMC 1457; S 3845), sharp edge bruise below bust, otherwise about extremely fine for strike.
Provenance
DNW 145, 13 March 2018, lot 354
SNC, December 2001, MC1259 - 'edge knock, practically as struck and toned - £125
Estimate: £300 - £400