Another poser: SM 2398 was for 1-ton 120" w.b. 4 x 2, for New Zealand, probably 1942 Models as well. Was this also for DD2 T-116-120 trucks?
As per my comments above these would be 120" wheelbase 4 x 2 pickups (there was no panel van variant) although there's an off chance they were cab / cowl chassis.