Worked on installing the rudder Trim Tab. Drilled-out the lower-most hole in the aft part of the rudder. Clecoed the Trim Tab to the hole and match-drilled nine #30 holes and then deburred the holes. Removed the rudder from the vertical stabilizer and primed the mating surfaces of the tab and the rudder. I wanted to rivet the tab to complete this section but I couldn't find AD-41 ABS rivets that are prescribed. Will order them from Van's and complete this section later.