I installed the nutplates on the mounting bracket and then put a coat of self-etching primer on it. I had to fabricate a little spacer to be able to set the LP4-3 rivets since the flange of the stringers prevent the nose of the hand riveter from fitting down flush against the top of the rivet.
I fabricated a small antenna doubler for the UAT antenna, then drilled it to the bottom of the fuselage. I mounted this 2′ aft of the transponder antenna, just behind the next bulkhead and right on the aircraft centerline.
