Watch List notes:

Half Dollar George III Octagonal Countermark on a Spain 4 Reales 1779S CF (Seville) countermark Fine, host coin GF/NVF, unlisted by ESC, Bull 1887 type B/1, listed as Rarity R5, with an accompanying footnote stating 'All octagonal countermarks are very rare, most on this (Bull's) list being unrecorded, comes with an old collector's ticket stating 'R2 Seaby 1953, Seaby No.612 75/-'

Estimate: 250-450 GBP