Match drill firewall for regulator bracket. I decided to use one of the nut plates that were installed for the heat valve cable clamp. I will not be using the cables so the hole would be filled anyway.
Remove all clecos, debur and dimple all holes.
Cleco doubler and nut plate in position.
Rivet doubler using 3x gun and tungsten bar.
Paint steel regulator bracket for corrosion resistance.