I think the answer to your question is, what are your capabilities? Mike apparently beat me to the post (-faster typer!
) but both of our strategies appear to be the same.
For me personally, since I have a CNC Plasma, I would cut a nice looking plate to match the frame where the bracket was to be welded. I would plan on cutting 4-6 ⅜" holes in the plate, and then use a transfer punch to mark the holes in the frame where the hole s will be drilled. If the new plate is 0.250" thick, mark and grind the areas on the bracket where you would have welded it to the plate so the alignment for linkages will remain correct. Bolt the entire bracket onto the frame with Grade 8 bolts and use nuts with Loctite. It will be there until the Master comes back.