Riveted trailing edge of rudder. Backing plate produces excellent results. Paniced a bit because I started in the middle and worked my way towards the edges. I missed the commentary in the instructions on how best to rivet the trailing edge. Checked for straightness and it was dead-on. I assume using 3M Epoxy helped vs. using Proseal. Used epoxy on the S51 kit for the skins and it worked like a champ.