Below you can see some renders from the 3D program. At this stage, I can say that making a trailer is 100% possible.
Trailer from photos will have a height around King Pin of 93mm.
You need to measure your truck (from floor to flat 5th wheel) and tell me your height (standard is 104mm). Then I will raise the suspension.

The sides will be unfolded - the lock is at the top (with a spring).
The posts will be tightened with one screw each - it will be possible to disassemble.

The two rear axles will rotate as in the original. To test is the arrangement of the servo - it will probably be relocated. I am considering controlling one servo.
Suspension on springs - airbag imitation

The blanks are for a wooden floor - best will be plywood, 2mm thick (can change to 3mm if you need)

In addition, supports will be included.

Construction - mostly welded.
Materials:
Frame - stainless steel
Boards and posts - 3D PETG printing (+ stainless steel lock mechanism [stainless posts need be tested on press brake])
Suspension - 3D printing Carbon fiber PETG + stainless steel.
Mudguards - 3D printing Carbon fiber PETG + stainless steel.

The kit does not include:
- wheels (rims and tires)
- axles (needed popular aluminium axles)
- servos
- wooden floor elements.

The kit will be delivered unpainted.
If you want to add any element (logo, etc) - feel free to write.
 
Overall length: 960mm

Expected time:
- cutting out metal elements (external company - 2-3 weeks)
- Finishing of the elements (bending, threading, welding - one week after receiving the elements)
- welding of the structure, assembly (another week after finishing the elements)