I needed to drill a mounting hole at the very bottom of the stiffener ring.
Then I cut and bent the brackets. I used scrap 0.025" strips to figure out the best method to bend all of the brackets. Nothing better than measure, mark, and bend with taped up hand seemers. Just with finger pressures, bends turned out nice. Had to make a few until I had the dimensions correct. But it turned out well.
Looks like it turned out pretty good. Happy with the result.