Re: Old dog learns new trick...Welding!
Those brackets are galvanized.
When I welded up the holes in my rear sprocket I ground off the galvanized coating on both sides, drilled the holes slightly over sized to remove the coating in the holes themselves and rosette welded the holes closed. Finished them off by grinding the welds smooth on both sides and painted the center of the sprocket black to protect the raw steel.
"It's a chinagirl. It's a sometimes fun little engine that often will break your heart. It's disposable.
Does not come with a fortune cookie."