oops - the original poster asked for "Art Deco" (not a GM name) through 1959.

Here is the one weak reference in the links I posted.

"In 1960, the Chevy C/K line of trucks was released for the first time. One of the most popular models from the C/K series was the Chevy C10, a half-ton, light-duty pickup. Several body styles were available for the C/K trucks, such as the popular Fleetside and the Stepside, which consisted of rear wheels on the outside of the bed, with a step located between the cab and the wheel wells."

Otherwise, yes, that omission seems odd?

Comments/observations from Jim Carter.
Here is a 60-72 Message Board.
Pinterest?
1960-1966 Ride Guides (for walking/talking encyclopedias)?
Classic Muscle - good words/write-up? but no pictures?