ID help please

[Bill Murray]

I am supposed to be pretty good at this but I am a bit stumped.

This photo appears on the Wermacht Awards.com forum and the poster is an author who wants to use it in one of his books.
It states on the back of the photo more or less "we captured this marvelous Russian Lorry with only 3XX km on it and are using it to transport our kitchen." He is looking for a positive ID.
It certainly looks almost new and there are several ID points to look at.

What appear to be US non-directional tyres
Spare mounted under the tailgate.
Garage door type tailgate??

The photo was taken in Autumn 1942 so eliminates at least some lend lease vehicles but I think it is either American or more likely British. I for a time called it a Gaz AA but the little plate under the tailgate is not seen on the Gaz vehicles and I am sure I have seen it on either US or British trucks.

Any help is appreciated and I will give credit to the author if anyone can ID it.
Bill