Well,
I did a little progress this last weekend on the trailer. I was going to break it down for blasting, but instead worked on the tailgate. I'm doing a very similar style tailgate setup as FlashHoles. My M416 had a tailgate already as shown in pictures above, but is was warped, rusty, left little for a good solid top design, and the whole thing was in rough shape. So I chopped off the hinges and ditched the rear. The person who did the design used 1/8 2" angle iron to frame in the tailgate. I chose to keep the tube frame side support as it would have compromised the integrity of the rear of the tub if I removed it. I welded 1/1 square tubing cross the top and bottom of the tub and welded in some 16ga sheet on the rear sides. Some clean-up of the shape is in order, but it's close. The top bar will serve as the base for the lid and provide stability of the open end. My tailgate opening is about 31x16 in size. I have already welded up the rest of the gate and need more sheet steel finish it off. I also need to get some hinges and latches of which I'm not sure what I want yet.
Next up... Add 1x1 angle iron to top of tub frame for flat surface to support a lid. Breaking down the frame for blasting and primer. Start ordering parts for worn out components.
Reviewing axle and wheel options. I want to keep the brake so I'm looking into spacers, new/used radials on stock rims, Cj rims, etc...