Here's the area in question..
I fabricated a plate with cuts in it to fit around the larger arm..
This was then tack welded along one edge..
Then the plate is carefully hammered and folded over the arm..
...clamped and welded down..
You can see I did the same for the shorter arm nearest to the camera in the pic above. I also added the regular plate to the chassis itself and welded it all up. Again, I was really careful to weld around the suspension so I didn't build up too much heat in any one spot. I also cooled each weld with compressed air.
Here it is after all the welding's done..
Job done...hopefully it won't break and I won't have to eat my words!