I have same generator as Randy. Mine is mounted on some sort of brackets attached to the frame. It's not in an enclosed cabinet. There is a door in front of it so from the outside it looks like it's just another enclosed cabinet.
'03 Freightliner FL112, 295" wheel base, with '03 United Specialties 26' living quarters, single screw, Cat C12 430 h/p 1650 torque, Eaton 10speed , 3.42 rear axle ratio