Looks great and wow, my old camping trailer still kicking around.
The M101 3/4ton mil frame is quite heavy. The box boat tongue by comparison is quite light. The Dexter axle should have electric brakes and a parking brake (both not connected). The lights look still to be magnetic. I didn't finish the build before I sold it to your seller. I also wanted to add a swing box for a kitchen off the back end. A pop-up awning is just tall enough to cover the entrance of the camper and large enough to give you plenty of awning cover off the back of the trailer. Perfect location for a kitchen.
The axle can be adjusted on the frame up to 20" by 5" intervals. This keeps the tongue happy with the weight location. I was surprised at the capacity of the mil springs when I pulled it around. There wasn't any jumping of the axle/frame on rough roads. The trailer frame absorbed it.
When you fold the camper closed, I used my camping chairs across the seats, placed the top on those, then flipped the bedding on the top and closed it. The canvas top should protect the interior from getting wet during travels, but it does have a tendency to gather air under it. I never got anything wet inside. Under the chairs are locations for your coolers and clothing bags. I kept sleeping attire under the seats of the camper.
Yah, the tongue is long, but the frame was put together before the slide-in camper idea came to mind. I wanted to build a camper on the frame and have a queen frontal sleep area (7' long) with a rear door entry and storage between (3-5').
If you are looking to do a SOA, I'd look at another all together different trailer frame, build that and swap over the camper and tongue box. You really can't lift the box by yourself off the frame, but I used furniture dollys to move it around once I pried it off the frame. The camper should be secured to the frame through several sheet metal screws through the wood planks along with a safety 'C' bolt in the middle. (I thought about getting rear-end and having the camper come flying off the frame.)
There is a 3500# Dexter axle so swapping hub to match your driver vehicle shouldn't be a problem. Good luck with it.
Edit: Oh, I towed it with a 4cyl/auto TJ on 34's.
