In the process of learning to see if the GSP method of mounting the rudder servo would work I discovered the solution to the extra servo tray. Glue it to the inside of the fuselage! Problem solved...

I guess my pull-pull geometry isn't quite right. The non-pulling side goes slack about half way through the rudder's travel...

Well -- mine is almost done. I need to finish the programming and set the CG. The box of little bits in now empty!