Great Britain 1955 2s6d-£1 "Castles" (Waterlow printing), SG536/9.
A very fine unmounted mint, with full original gum, marginal set of four.
One of the most popular QEII stamp issues featuring the most famous castles across the United Kingdom:
2s6d black-brown - Carrickfergus Castle, Northern Ireland
5s rose-carmine - Caernarvon Castle, Wales
10s ultramarine - Edinburgh Castle, Scotland
£1 black - Windsor Castle, England
The bust of Queen Elizabeth II is taken from the portrait by Dorothy Wilding.