In looking over your photos and studying the windows I think the original use may have been the schools Athletic or Band bus. Most all of those types of buses had the under-body storage and/or racks above the seats. If not that, it was special ordered as a inter-local transit bus for short trips between small rural towns. Just my thoughts.
Yes, my wife's grandfathers business was "Joiner Transit" that serviced the towns of Russellville AL, Florence AL, Iron City Tenn., Muscle Shoals AL, and others. They had a Greyhound service for a while and eventually went into business for themselves with "Joiner Transit" (their name). From what I was told they had around 20-25 buses total.
