The first one is 38 or 9 but the rest are older. Note the front fender sweep to the running board and the rear fender tails on the last four. I think they were showing off their newest truck in this photo. Tim
And..........bigger Panel -- note hubcaps for a 3/4 tonner
The next 2 with the split windshield look like 1/2 ton panels, maybe 1937?
The flat windshield in the 4th one could be 1935-36 and the last one with the split windshield another 1937.