M7 Priest self-propelled gun of the 19th Field Regiment, R.C.A., Normandy, July 1944. Left to right: Bdrs. D. Nashawa, G. Harper. Full names of 'the "Wacky" Seven are - top row painted directly onto the hull side DICK and GORD, second row on Maple Leaf background HARRY and JIM, third row also on Maple Leaf background BERT and BRES."
Maybe the two Bombardiers are Dick and Gord? Note the vehicle has the additional or extended side armour (see top left). It could have well went on to be a Kangaroo.

Canadian Priest