Here’s a similarly numbered Sunbeam staff car, M-19895, pictured August 1918 on the Western Front in France, captioned: “A Sunbeam staff car used by officers”. Others, numbers unreadable, were pictured in France in 1915 through to 1920.

The Government commandeered nearly all Sunbeam output from April 1915, “The Empire First, Private Orders After”; thence they supplied staff cars, ambulances, aero-engines and planes throughout the war – maintaining profits along the way. They emphasised their patriotism in adverts by picturing an army 16-20hp model next to the Pyramids, quoting satisfied officers using their own cars and promising post-war availability.

From an April 1916 Sunbeam advert: “The cars deserve the utmost praise. Their drivers cannot speak too highly of them. I have driven other makes of cars, but they have not given the satisfaction or endurance which the Sunbeam has - From a driver at the front.” Perhaps the opinion of M-18917’s driver?