Demountable camper group

That's very similar to the system used to bind the buck to the chassis for a 5th wheel conversion. Really good idea in my opinion.

Well, given that useful info, I reckon a piece of flat bar, bent or welded into a U shape, with threaded ends, would mount around the chassis rail and spread the load. I'll see how mine ends up, once i've got a pickup.

Best not weld the chassis. They are all designed to flex (if they don't flex they break) and you could so easily louse that up and create an unwelcome stress point. Big truck chassis are usually riveted rather than welded for just this reason.
It's usually easy enough to use the original body tub mounts, usually just using a longer bolt through the original mounting extending into the inside of the body tub (drill it first!). Add your lug or 'eye nut' and you're done.

Best wishes

Gary

I like the U-bolt around the chassis. Not so keen on the smaller U-bolt that sticks out horizontally through the wheel-arch into the load bed. Strikes me that there could be a lot of force trying to bend that U-bolt upwards. Though I concede it is a lot better than just having that small U-bolt attached only to the thin steel of the load bed from where the force is transferred to the load bed mountings.

Steve.

In the pictures I have seen of the eye bolts used here they normally go straight downwards and (Im guessing) if the back set come down to meet the chassis rail then the fronts should as well shouldn't they