Watch List notes:

MS64 | The Undated Mule | Elizabeth II (1952-), Undated Twenty Pence, [2008], edge plain, 5.01g, 12h (S.G4A [4631A]), the first currency coin struck without a date for circulation in Britain since the reign of Charles II, a famous modern rarity, much as struck, in NGC holder, graded MS64 (Cert. #6295117-019).

Estimate: £70 - £100