Not exactly sure what you are asking by the title. How many shortbeds were made??
There was not much "cool" factor in owning trucks in the sixties. People that say there was probably weren't there in the sixties or their memory has changed history.

Mostly people bought them for utility so the long box made more sense. Wideside or stepside the long box is way more plentiful.
Now go to auto dealer today and try to find any "company" truck or PU. Mat floor and rollup windows. Non-existant in Suburbans. GM made a "work truck" for awhile (model said "WT")...came white and they all had the same few options.