Another recommendation on the Yak is to imrpove the beveling of the control surfaces at the hinge line.

On my Elevator/Rudder I had to leave a noticable gap to get the 30-40 degrees throws (needed for 3D etc). Same for ailerons.

Also a fiberglass cowl/wheel pants would be a nice addition. SAE (instaed of metric) hardware would also be nice.