Jim,
Not sure about the RV-10, but on the RV-7, the brake pedals consist of the pedal plate, two angles that get riveted to the back of the plate, and a side arm that attaches to one of the angles and is bolted to the master cylinder. The bottom of the side angles get drilled to match the tabs on the bottom of the rudder pedal weldment. This is where the brake pedals pivot. The rudder pedal weldments are predrilled, but you have to drill the hole in the side arm that attaches to the master cylinder. Where you drill that hole determines the angle of the brake pedal.
You can look at my website at
www.trv7.com to see all of the steps that I went through to fab the pedals. Note, there was no guidance from Van on how to set the brake pedals relative to the rudder pedals, but I think I got it right (look a lot like what Roberta did).
Tracy.