Patching is good but metal should be same thickness and close to same type. You won't want SS patch in cold rolled steel frame or the tower wall. You cut a patch w/ hand cutters then metal is likely too thin and weak.
You should have use open hole to inspect the frame inside using mirrors, small camera or bore scope.
Missing Tower wall area should have overlapped patch that spans the frame patch and cut off tower.
Stick and TIG and other wire feed welding to frame might be ok, Not so much to weld on the struck tower. GM and others uses Spot welds for more reasons than just cheap. Spot welding won't heat a whole panel to screw up metal hardness etc. Even when have a lot of them.
------------------ Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should. (Jurassic Park)
