Watch List notes:

George III (1760-1820), Proof Halfcrown, 1816, type 1, first laureate head right, bare shoulder before, rev. en medaille, crowned Garter shield, edge milled, 14.06g (ESC 2087 (614) R2; S.3788), attractive and even dark cabinet tone overlying brilliant surfaces, good extremely fine, the reverse much as struck, very rare, in NGC holder, graded PF61, the current finest certified by NGC (Cert. #4861492-004).
Provenance
SNC, June 1980, no. 4826 - "very rare, a magnificent coin, with an even dark tone, F.D.C." - £900
Estimate: £2,000 - £2,500