I used the prototype braces and made the ones out of the 1/8 aluminum angle. It worked good to get the geometry close and then do some final tweaking to get them just right. I used the support angle on the backside of the firewall where the rudder pedal cable attaches and for the left side I drilled out a rivet in the center of the engine mount weldment that was the perfect location for the other support bracket bolt.
I cut angles on front support angle. I got everything where it needs to be and all there is to do is drill the holt holes for the two support locations on the front angle and the braces. Now I can breath easy because it came out good and no big OOPS during the process.
Will drill the front supports and do a little trimming and then move on with the build afterward!