My first post was about a body rotiserrie stand not a roller type, I misunderstood!
I have used 2x10's or 2x12's on edge made into a box, much like a sandbox about 4ft square and ran a 2x6 across ends to mount swivel casters on (4" or bigger) and set the cab on it. Nice and higher too. I made sure the wood hit cab where the front mounts bolted on frame and about anywhere on back floor area. I have also used the upper frame from my COE frames to make similar roll around for them by removing from main frame and bolting to the above rack. Then it uses the orig mounts for cab. Your dad may have some 4ft lumber laying around to make this. Just use 16d nails ot lag bolts in corners, Nothing fancy. Also you can buy those wood and carpet made up racks at some of the Import tool stores for cheaper than the casters will cost probly and just add lumber to it to fit cab.
