Didn’t like the right rear bracket, so I laid out holes etc on a new template and changed the shape of the bracket. Cut out the new .063 bracket with a hacksaw and dremel. I will attach the new bracket to a piece of 1” vertical angle with screws and nutplates. The angle will attach to the crossmember. I drilled a couple of holes to #27 to attach the bracket to the angle, then drilled the angle for nutplates. Put a light countersink in the angle to attach the nutplates with some NAS1097 rivets. Cleaned up and primered the parts. Then I squeezed the rivets to attach the nutplates—had to use a miniature nutplate at the top of the angle, or I would have an interference issue with the ICOM radio tray. Used #8 screws to attach the bracket to the angle. Installed the panel with radio stack—now have a very solid mount.