Watch List notes:

George IV (1820-30), Proof Crown, 1826 septimo, bare head left, rev. shield with crest, inscribed edge (L&S 27; ESC 2336 (257); S.3806), beautiful dark and iridescent tone overlying brilliant surfaces, a delightful example of this rare issue, with only 150 stuck, practically mint state, in NGC holder, graded PF63+ (Cert. #4861253-002).
The current finest example certified by NGC
Estimate: £8,000 - £12,000