You are correct, a bar should connect the right Touch-Control arm to the drawbar for depth control. It is actually a 3 bar assembly that allows adjusting the length. I don't know of anyone that successfully used the plow without that link. The link may not be easy to find. You could check with JP (link at the bottom of the page) or put a wanted ad in the vine on this site. Some people have gotten the dimensions and made a link.