We owned a 1984 Peterbilt cabover. It had a massive 72" sleeper as part of the cab, with a 8x8 condo behind that. 400 Cummins BC, 8-speed. 276" wheelbase ate up parking-lots.
Between the cab/sleeper and condo, the conversion folks used simple upholstery vinyl with snaps.
Besides leaking water and wind and exhaust, it required two boys and a mule about a week-and-a-half to unfasten so we could tilt the cab for a looksy.
I am interested in your solution.