KH question

Steve, Thems cast iron. IMO not something to MIG.
Possibly could be brazed with a wear resistant filler rod.
To weld they need be heat soaked. Oven is best, heat table will work.
Then welded. then slowly cooled in the oven or on the table or whatever.

Another option might be tacking down shim stock. I'd even consider using an epoxy made for steel to hold the shim down. The ears of the pad backing plate will trap the shim. Only place they could really move is sideways.