I am holding a straight piece of aluminum angle next to the trailing edge of my rudder to judge the straightness of my rudder. There is a risk that this can come out warped, bowed, and/or wavy. A bowed rudder will not fly well. As you can see, mine came out reasonably straight. The other risk with this task is that it is easy to no know when to stop with the rivet gun. There are areas of very small waves in this edge that I plan to leave out of fear of making it worse by more riveting.