Watch List notes:

(g) George IV (1820-1830), Half-Sovereign, 1821, laureate head left, rev. crowned garnished shield, edge milled, 7h (Stratos 53; Marsh 403; MCE 482; Spink 3802), a key date in series and crisply struck gem, with cartwheel lustrous and flashy obverse fields twinned with frosted reverse surfaces, a hint of bag marks otherwise choice, practically as struck, very rare, in NGC holder, graded MS64

The Hayleigh coin in our Spink Stratos sale (NGC MS64*) brought £7,800 ($9,750), the present specimen is quite reminiscent of that gem despite lacking the star designation.