Fiddled around some more with the wingtip rib location. Thinking of removing the rib flange where it interferes with the hinge and riveting a new flange to the rib to compensate for the hinge. That would give the tip the full support of the rib without removing a large portion. Also match drilled, with a drill stop to prevent damage to the pitot tube plumbing, the pitot tube mast to the pitot tube after much measuring and marking. Always stressful drilling into new high dollar parts. All went as well as could be expected. Not sure if I'm going to use 6-32 screws or 6-40. Don't really think it makes much difference.