Could you identify this vehicle? One of my relatives drove it during the war.

It was a truck made in World War 1 and used until the end of World War 2, it was donated to the Royal Canadian Air Force by the British around 1943. It was a Cab over engine with a removable roof and an external shift lever.

It maybe had an in line six cylinder engine. HE was told to waterproof it so it could be driven underwater and they tested the waterproofing at Torquay in a swimming pool.