Thanks mo
Yes bracing is from top plate to post.
I have not determined how much arc but I will try your 2.5".
I have also decided to go with a 4" width on the braces, thanks for the peg suggestion.
I have forstner bits for cutting the mortise however I am limited to 3-3.5" depth. Any ideas other than chisel for more depth or through cuts?
I appreciate the feedback.

Lloyd