I match drilled the inner floor stiffeners. I had already drilled the left inner stiffener a few days ago. I used that part as a drill guide for the other stiffener.
Here are the stiffeners clecoed to the bottom skin.
I drilled the optional lightening holes in the F-6118 Rudder Pedal Brace. The mounting holes and the flange clearance were also cut into the part.