On the truck bed, closest to the truck cab , I welded a winch holder, bolted down using the truck bed bolts.
At the rear of the truck bed is a large 1/4" metal plate, with 2 holes, 35" apart, bolted down using the bed bolts.
The plate extends to the rear where I made a hinge with 3/4" metal rod going through it. I cut it in half, and taps both ends so I can use a slide hammer to pull them out.
For the first 8ft long metal rail section, I found a largest pieces I have, but I can also handle at the end. It's 4" tall.
It has the other half of the hinge that attaches to the truck. It is also supported by the lift near the mid section (1300 lbs lift). I was pondering make 2 large adjustable stands to keep the middle section strong, but I use the available lift instead.
2 bolts are used per wood piece to hold down.
The end, I welded 2x 1/4" thick pieces that just rest on the final metal ramps.
For the short metal ramps, 5ft wood is used, and 4 front leg extensions were added so they can't tilt forward.
The wood peices are held together using 1/16" thick metal pieces.
All non-swirvel wheels are used for the dolly.
I also put 2 small metal ramp pieces to climb from floor to the wood.
Moving the mill up, I used a winch, with another rope tied to top of the mill and a person hold it, in case it rocks and tip over. And another rope at bottom to prevent run away toward front.
Moving down was much easier, just use 2 ropes (1 as a backup). and wrap around strong anchors a few times to slowly release it, and move down very slowly, use 2x4 to pry it as needed.
To prevent tip over of the mill, I position the mill toward the front of the dolly, and also moved the head rail toward the front of the truck.