Hans:
The emblem on the bonnet side just says Dodge.
My "good" references on Dodge are primarily for the light duty models. However, a D1 is a 1/2 US ton, a D2 is a one US ton and I would imagine this is probably a D3 based on that logic. In US measures, 1000lbs is 1/2 ton, 2000 lbs is 1 ton and so on.
I will continue to look for a better reference.
Cheers, Bill
PS: Cliff, we have to stop agreeing like this, people are starting to talk. I also have to disagree with Hanno pretty soon