Yes it's been cut for access, probably had a different engine in at some point. Or A bad rear end crash... Or a cut and shut... Or that rear piece was cut out to replace with a different chassis number...
Cut and shut, I'm pretty sure there isn't much of the original bus left, it feels like I've replace half of it in the last 3 years.
I drive my lowered bus up on Halfords ramps which then give enough clearance to lower the engine on a trolley jack. Of course this means the engine has to run to get it up there... I remove the rear bumper or push up slightly with the 4x4 high lift jack on the rear suspension tube to slide the engine out. I do not use axle stands because my parking space is slightly sloping tarmac and the whole setup would have a tendency to falll over...