Why send him elsewhere? He's here asking the question and many of us have interest in both lines. Others can chime in, but since most of the Canadian built GMC'S of that era used Chevrolet engines, some guys use Dupli-Color Engine Enamel code DE 1611, it's pretty close to the original color gray. Or the colour is Grey, since it is Canadian.

I think this one is in a 1940 Canadian built GMC