This Pedestal post box near me is a variant of the Wall box and Lamp post box, an early economy measure originally used in rural places where, presumably, the Post Office believed there were not enough letter writers to warrant a full size Pillar Box. This one is a fairly recent one as it carries the E11R cypher for Queen Elizabeth the Second.
Apparently there is a Letter box study group which has identified 800 different types of letter box. Who knew?
Graham Findlay Watercolours 