Now Then..
There are 2 - M10 threaded holes in the rear cab pillar, 120mm centres.
Make a plate to suit, weld a short length of male PTO tubing to it parallel to the side window. This can all stay in permanently so paint it when yr done.
Now, make a plate to accommodate your control box and weld a piece of female PTO tube to it so the control box is at a comfortable position with access to the tractor controls.
I've made many over the years but no pictures to hand I'm afraid..
Well, there's a good reason to learn. My last welder cost £250 ish, you could get a much cheaper one off Amazon or Ebay. Weld quality isn't critical for what you're doing.Excellent except I have neither a welder or the skills to use one. Is it possible to buy something?