Manual seat adjustment mechanism

My drivers seat in my 76 300D leans back on my right side. I have taken the seat apart and noticed the arm connecting the seat back to the seat base is loose. This is a pressed steel mechanism that is connected to the left side with a square shaft. I am guessing the square hole on the right side has wallowed out. I would appreciate any suggestions on getting this apart so I can weld, drill out and re-square the hole. If not I guess I will get a new seat at the salvage. Thanks for any insight.