Now we know: this is a Renault Army Truck
We got several answers on our question What brand of car is this? We consider this one the most convincing:
FERNANDO URQUIJO: The car is a Renault AG. The famous "Taxis de la Márne" were also Renaults.
Renault was famous until the 1920´s for putting the radiators behind the engine cover.
Thanks Fernando! - RR.