The conversions were done by truck body builders in the general area that they were sold. In the Denver area, Winter-Weiss did most of them, but, I believe that Jacobs Equipment did some also. It wasn't a difficult conversion and was a lot cheaper than a full sized bus. I can remember picking them up from Winter-Weiss for my dad's dealership until the mid 60's. We were in Northern Colorado and there were, and still are, a lot of small districts that had bus routes that could, at times, cover 50-75 miles one way. The driver usually lived at the end of the run and would pickup 8 or 10 students and bring them home. The school bus standards weren't very stringent and the conversions were pretty primitive. Lawyers hadn't yet realized their power. I do remember that they rode hard and, because they operated on unimproved road, didn't last more than 5 or 6 years.
