Watch List notes:

PF63 | George III (1760-1820), silver Pattern Shilling or Sovereign, undated (1816), by William Wyon, laureate head right, GEORGIVS . III . DEI . GRATIA, rev. square shield, garnished and crowned, BRITANIARUM REX FIDEI DEFENSOR, edge milled, weight 5.66g (Bentley 933; ESC 1245 R6; Bull 2182 R6). Toned, has been graded by NGC as PF63 and of the highest rarity with Bull citing only three known.

NGC Certification 6321659-004

We note the example in the Bentley Collection in 2012 sold for a total of £8,160.
Estimate: £6,000-8,000