Watch List notes:

(g) PF63 | George VI (1936-52), Proof Sovereign, 1937, by Humphrey Paget, bare head left, rev. St George and Dragon, edge plain, 12h (Stratos = Gemini 276; W&R 439; S.4076), some light rim stipling at 11 o'clock and hairlines in fields, otherwise extremely fine, in NGC holder, graded PF63 (Cert. #5878626-008) [Tied 1 of 49 / 147 Finer].
https://www.ngccoin.com/certlookup/5878626-008/63/
Estimate: £1,200 - £1,500