you won't have much luck finding any info from the numbers troy, your RHD trucks were from Canada, but had a numbering scheme designed by your ancestors, not ours .... I'd say the roof treatment is likely military, but it's possible all the differences were done by Holden .... as close as anyone could say it's '41-'46, from the park lights on the headlight pods, they all had the opening windshield, but those external hinges on it are not GM of Canada, nor is the rain gutter over the windshield!!
it's historic value will only be to you and your mates, and if you don't know that history .....
Bill
