I'm not convinced about a W&G du Cros connection - the W&G script is normally very different with an underscore. To my eyes it like W&C instead (though no idea who that could be).
Hi Peter, I've seen pics of later vans in RAF use with BABS (blind/beam approach beacon system) gear - serials RAF 156717, RAF 156992 and RAF 157062. Do you have the side panels? If so, does the passenger side have some vents at the front?
The first is a Karrier WO6; and the second a Morris Commercial D type.
Info on the company here:
TRAINING TERRITORIAL PERK ■ ZEL IN THE USE OF SIX -WHEEL] | 19th March 1929 | The Commercial Motor Archive
WINTER WORK FOR ARMY | 3rd December 1929 | The Commercial Motor Archive
I see this Box, or a similar one, is up for sale: Humber Heavy Utility Car 4x4 Prototype Spring Front End, Restoration Project. - Medium - MILWEB CLASSIFIEDS
Some IWM pics:
E18646: THE BRITISH ARMY IN NORTH AFRICA AND THE MIDDLE EAST 1940-1947 | Imperial War Museums (iwm.org.uk)
E18647: THE BRITISH ARMY IN NORTH AFRICA 1942 | Imperial War Museums (iwm.org.uk)
E21853: THE BRITISH ARMY IN NORTH AFRICA AND THE MIDDLE EAST 1940-1947 | Imperial War Museums (iwm.org.uk)
Hi Hanno, there's a 1/2 ton carryall pictured here (just!) in Burma (Ref: CF327): ROYAL AIR FORCE OPERATIONS IN THE FAR EAST, 1941-1945. | Imperial War Museums (iwm.org.uk)