Jeannie beat me to it but yeah theyre not all that rare of a build for the time, but I think (disclaimer: i dont know anything) theyre mostly broken and trashed since they were used in work places. Everyone wants a short box for modding into a mexican lowrider anymore.
They look better than most any other body type to me though. Longbed gives you good solid looking steps and a smoother ride, and being a stepper you get the neat detail factor. Its a win win!