I used a low-mounted air cylinder on the left side and a rocker arm for my X2 drawbar. This is Hoss's engineering; ratios, air cylinder, Belleville springs, etc. All I did was rearrange some of the parts.
The top rocker has a ball bearing because I had some on hand, and I figured it would make a nice (non)wear surface. The top rocker is split and clamps to the rocker shaft, which is welded to the long lower arm. You have to unclamp the top rocker and then slide the shaft out the right to disassemble.
The side plates are .090 steel. The bronze bushings came from Lowe's, and are a thumb press fit into some tubing I had on hand.
One change from Hoss's design is the air cylinder, mount, which I don't have a picture of yet. I made a bracket to hold it by the nose, running back to a bronze bushed pivot, so the cylinder can swing as it moves the lever. Hoss's design uses a slot in the lever, which apparently works just fine.
I had to make some spacers for the side pieces so I could change the belt. The clevis had to be shortened to make everything line up right.
I'll post some better pictures later.