Grarge Accessory Series Shell Forecourt Sign
A Shell forecourt sign as fitted from the fifties up to 1966 , the end of the period when Shell and BP worked as a combined retail force in the UK, although their demerger was a decade later. Although I have yet to find a UK photo of this pattern of post, I have managed to find a BP one, as well as a Shell one in the USA, so I feel it's almost certain that the Shell version must have existed in the UK, too.
As with the pumps, older pattern forecourt signs often survived for many years in outlying areas, long after rebranding had seen them replaced in busier locations