I have did the pitot tube mount installation somewhat backwards. When I installed the backing plate and the support structure for the pitot tube I ignored to match drill the bottom wing skin so now, in order to make the mount removable after the skin is riveted on, I had to mark the holes on the wing skin to match the already existing holes on the backing plate. Made a lot of work for myself. Had to cleco the bottom skin on the wing and make the marks in a very tight environment. This took a lot of time, but eventually it all came out OK. I also had to determine the rivet length underlain by the backing plate. The picture shows the final result.
