Mike, I think those OSB laminated beams are way, way over the top - unless it's a design for a cargo deck trailer. A teardrop body provides itself with all the support it needs and the T-shape chassis in your graphic is all the chassis it needs, so I think all those beams are superfluous.
I guess I can't keep saying often enough that house building techniques and trailer building techniques are not the same and it's not necessary to build a 'floor' to sit a teardrop body on.
I would like to see some big warnings on posting Dave's (dwgriff1's) teardrop in a part-built condition. Most importantly the photo doesn't show the tongue braces from the front of the body to the tongue that were added after the body was skinned - they are the main thing holding the tongue and coupler in place.
I also still wince when I see the step change in the size of the wood tongue where it joins the body. Because of Dave's design and the tongue brace, he has 'got away' with this (as I see it - he would word it differently, I'm sure!), but it's still a very undesirable design detail that I wouldn't want to see anyone else copy.
Building a Kampmaster without a metal frame is a tall order. I think it could be done by making some diagonals to connect the front of the A-frame to the upper sides of the body - so there would be upper and lower A-frames where all four pieces met at the coupler. But this would be very complex to design (those diagonals slope in plan and elevation) and some clever epoxy joints would be needed.
Alternatively Mike's laminated beams could be used as A-frame members but I'm guessing they would need to be at least 12" high, so either the Kampmaster has only about 36" headroom inside or it gets jacked up in the air by those 12", neither of which is appealing.
Andrew
Edit: I see you managed to duplicate what I was writing, while I was writing it!