Riveted together parts that make up the vertical spar and ribs of the rudder assembly. I was able to use the numatx squeezer on all the rivets except the one pictured with the red circle. No combination of yoke would fit around the flange and rudder horn. I tried various options and finally decided to buck it using a straight cupped tool in the rivet gun with a tungsten bucking bar. It worked well. Another minor issue was using the rivet gun to install the zip tie bracket (not shown). The nose of the rivet gun i was using was too large to fit snug against the LP4 rivet because the rivet sits down in a recess of the zip tie bracket. I eventually made it work but it could have been better using a stack of tiny washers in between the rivet gun and rivet.
