Watch List notes:

BRITISH COINS, Elizabeth I, third and fourth issues, sixpence, mm. acorn (1573-4), small flan, crowned bust l. with rose behind, rev. long cross fourchée over shield, date above shield (S.2561; N.1997), some weakness, otherwise toned about extremely fine
With old ticket recording its purchase from Spinks in 1959 for £1.

Estimate: £200-250