the RCAF sounds good. the site where this is at was over run with Canadians in WW2 training for D DAY. its not far from Coolham which I belive was Canadian Spits under Bader?
i ve measured the tyre and wheel, but no obvious markings. plus another picture of the other side of the rim
tyre - 760 x 200 mm
rim 340 mm
spindle/axle 30mm