Watch List notes:

(g) MS64 | Elizabeth II (1952-), Sovereign, 1957, first head, narrow edge milling, 8.00g, 11h (Marsh 297; Spink 4124), choice, practically as struck, the edge variety unique to this year of issue, in NGC holder, graded MS64 (Cert. #6295130-011).
Provenance
The Lansdown Collection of Guineas and Sovereigns,
Estimate: £280 - £320