I can tell you that the front clip and rear panel are of a Ward body on an International 3800 Chassis.. it looks like a later model (right before rename to AmTran) ward.. maybe 94/95. the windshield is what gives it away.. the rear clip is shaped much like an IC / Amtran which came from Ward..
Ward ---> AmTran ---> International ----> IC is how the body naming went.. Ward was bought at some point by international.. I cant remember when.. once bought, their bodies were only placed on international S-series and 3800 chassis..
this wouldve been post-purchase and international did do some different types of busses in small quantities.. whether this was once a School bus or not I dont know but if it was, it wouldve been stripped completely down to ribs below the roofline and reskinned. the skirting shape looks alot like what Ward used on their FE busses with the underbelly storage bins (or some were ordered low-skirted in some cities for some reason)
-Christopher