OK, some additional information and thought...
Thought - eliminate the intermediate frame, mount the bed directly on the main frame. But that has lots of complications, clearance issues, would need wheel wells tubbed, and probably just look weird.
Information (measurements)
Height of LMTV bed from ground: 60"
Height of LMTV primary frame from ground: 44"
Total length of LMTV bed: about 150" (about 12.5')
Distance from front of LMTV bed to back of cross-bed storage bins: 60"
Distance remaining from back of cross-bed storage bins: about 88". Split that into two 44" sections.
Did not measure to top of intermediate frame, that would be part of the sectioned bed
Height of fifth-wheel overhang from ground: 62" (roughly based on leveled camper). This is not adjustable without putting a lift kit on the camper suspension, raising it even further. This means only 2" between bottom of overhang and LMTV bed. Not enough, and most of the reason for this mental masturbation exercise.
Height of fifth-wheel pin: 54" - though this is usually adjustable at the pin box with about +or - 4"
Length from fifth-wheel pin to front of camper: less than 12" - not a lot of distance needed forward of the pin for straight-ahead driving. However!
Width of fifth-wheel, measured from center of pin to corner of fifth-wheel: 56". This is more than half the width of the camper (48"), but is the minimum radius needed to clear forward of the pin in a turn.
Based on length to cross-bed storage and radius of camper, the pivot point could be no more than 32" from rear of frame, or at least 116" back from front of bed. Which means that the pivot point would be about 10-14" behind the rear axle centerline. This could be compensated with a sliding fifth-wheel hitch like used for short-bed pickups - saddle slides forward for straight-ahead driving, slides back to clear front of camper with back of cab for turns.
Height of primary frame (44") minus height of fifth-wheel pin (54" nominal) allows height of 10" for fifth-wheel saddle, or similar length for a fifth-wheel-to-gooseneck ball adapter.
Next, explore what's under the bed that would have to be altered if the bed is removed. For sure, I'll have problems with the in-bed airdrop sling fittings. Well, maybe not so sure, now that I think. Will have to dig out the tape measure again...
