I only know part of the history of my hoe. It ended up at my dad's place. I'm not sure if it was because of some trade or if somebody just abandoned it. My dad accused it of being home made. I always thought it had enough resemblence to Green's hoes that it might be one of his early manual units. In any case, it came with a mounting bracket for a Ford and I made one for use on an A or Cub. I have tried it a little bit. It is definitely a handful. If I was going to actually use it much, I think I would at least try to modify it to use the Touch-Control to regulate the depth. It will reach out farther than where it is shown in the picture, but gets harder to handle. You will want to keep your work in as close as possible to the tractor. You will have better control and the side draft on the tractor will be minimized. Work the row from both sides and you only need to reach as far as the actual line of the vines.
Some grape hoes were made more like Gerry's sketch, except usually braced back to the bell housing. Effectively it would be similar to what you were talking about with your Cub-22 mower, except made of sturdier parts. The Touch-Control connected to that brace for up and down. It was made to telescope and a hydraulic cylinder could run it in and out. You might be able to apply some of this to Gerry's idea to develop it some more.
Do you have a Cub-54 blade? Maybe you could belly mount it and replace the blade with a tool bar. This gets you into something that is likely to be more work to swap out with your sickle bar mower or other implements.
By the way, your comment "Then pulling out moving in or out a bit and redoing the back-n-forth bit." reminds me of one warning. Don't try to back up with your digging tool in the ground, especially if you just attach to the universal mounting frames. Pressure backwards may break the front bracket of the mounting frames. If you go with something like Gerry's brace, you will probably be OK.
Here is a page I ran across. It is old news but maybe it or something it links to will be useful.http://www.nnyagdev.org/press-releases/press-05-20-08.htm