Pic from left rear shows odd rear door arrangement and side vent for rear engine. Front grill makes it look like an FE. If that's the case, bolting a RE to an FE bus is not out of the realm of doable. Again, what is the shortest FE bus out there?
Coachwork: Crown, integral. (With 2kW of tiltable solar)
Chassis: Crown Supercoach II (rear engine)
Engine: Detroit 6V92TAC, DDEC 2, Jake brake, Allison HT740
Rated Cap: 37,400 lbs GVWR
Just bear in mind that a short pusher may have squirrely handling, especially when the roads are wet or slippery. With such a difference in weight front to rear, you could get a "tail wags the dog" feeling with all that weight behind the rear axle and not much in front to counterbalance it. The 36-foot versions of my bus did not have the poise or balance that the 40-foot versions like mine have.
The local school district here has some short Thomas pushers, maybe about 30 feet long or just over, and they're the shortest RE school buses I've ever seen. If you want a good-handling shortie, buy a short mid-engine Crown!: http://www.crownisking.org/culacobus.html