Removed right bottom skin and pitot/AOA tube and mast. Harry Manvel helped flip wings to do top wing root nut plates. Discovered assembly error: nut plates for aft wing root fairing should have geen set in the spar flange. Drilled out rivets, removed rivets and reamed tab holes out to #30 for blind rivets. Drilled and countersunk holes; riveted nut plates in place with CS4-4 rivets.