Well, let's see . . . according to Divco's sales literature, this style of delivery van was produced from 1956 through 1966 with few if any styling changes. It was produced in models called 11, 12, 13, 15, 40, 41, 42, 51, 52, 57, 71, 72, 114, 124, 134, 154, 214, 224, 244, 334, 364, 364HD, and 374 - depending upon the motor supplier (Continental, Hercules or Divco's own "Super 6"), horsepower (47 to 128), the wheelbase (117" to 130"), and the cargo capacity (3.5 to 7 tons). Divco used the same artists rendering you posted over several years in many brochures and for numerous different models, as they all looked the same. I'm not sure how to specifically name the particular year and model number they called it in the source you posted it from, so with all the information above, everyone can have a turn guessing. I'll put in my final guess as a 1956 12' Divco Dividend with a 130" wheelbase and their own Super 6 motor . . . as that is what the exact picture you used shows in that year's brochure . . . but again, this same illustration was used for other years as well.
Divco Van, called Dividend, sometimes spelled as 'Di Vidend", produced 1956-1966, Model Types as listed above.
So if my guess is incorrect, the "right" answer is in there somewhere.