OK here is my progression on the trailer.
Its getting close to being finished.


The trailer is made out of wood 5/8" ply secured at all seams by 2" X 2" angle iron, glued with liquid nail, bolted with 1/4" bolts every 8" apart, and 2"X 4" layered ever 3' on the inside also bolted to the angle iron. The door will also be wrapped with angle using heavy duty barn door henge's and the lock, I will be using a cam lock. I plan on welding plate on each side of the lock so it can't be cut.

Cam lock, its the kind you see on the back of those 18 wheeler trailers, long shaft from top to the bottom of the door with a handle that swings over the top of the half that you lock, at the top and bottom of the door, it has hooks that latch into welded eyes.

If I had it to do over again I would have used sheet metal siding instead of wood.