Rare National Benzole Mixture 'Open & Shut' sign.
Recent frame work has been added to match the original frame.
 
Dimensions: 71 x 51cm
 
National Benzole was founded in February 1919 in a room next to the boiler house of the Gas Light and Coke Company in London's Horseferry Road.
In the early years of the century, benzole production had been small scale. But, because it was as good at propelling shells as motor cars, production was expanded massively during World War I. 
In 1928, Mr Mercury – startlingly naked – leapt for the first time from the pages of the national newspapers.
Mr Mercury, in National Benzole's black and chrome gold corporate colours, became one of the most powerful marketing images of this age.
Almost every service station in the 1930s had a National Benzole pump, for single-brand sites were unknown in those days.
Eventually Mr Mercury's head was used as the brand's logo.
National Benzole joined the Shell-Mex & BP family in 1957 but continued to trade separately. By the early 1990s the brand name was phased out in favour of BP.
 
source: https://en.wikipedia.org/wiki/National_Benzole (editied & citations removed).