Barry, if the hitch idea is anything like the re-engineering of the Spartan I'm sure you'll figure it out and it will be a technological breakthrough!
Have you drawn this yet?
In the recesses of my adled mind I seem to recall from trucking days a setup with straight truck / trailer combinations that had a long ...very long.... A frame to a drop down hitch behind the rear most axle. If I recall it was a pintle type hitch. I've seen this on the covered car carriers way back and then have seen it also on tandem dumps with trailers.
You might find some ideas in the commercial trucking arena that would help you avoid reinventing the wheel so to speak. Not that your reinventing I've seen so far leaves anything to be desired.
Pintle hitches work great to solve a lot of problems but also create some unique ones too.
We'll be watching to see what you come up with.
1984 28' Funeral Coach
Former Rolling Showroom & PuttLab (now party bus)
"I'm not an expert. But I did sleep in an Airstream last night."