Today KLH & I started to install the rivnuts for the tailwheel mount, a bit time consuming as we needed to ensure the correct seating of the rivnuts through all of the layers of material. KLH helped me by exerting pressure to the appropriate rib flanges, thank you. I have ordered more 4mm rivnuts with a larger grip range as the ones I have are just a little short to secure the longerons too. The lower forward rivnut flange on each side is preventing the mount from fully seating so I think I will need to trim those flanges a little, I'll wait till all of the rivnuts are in though. As the vertical stabiliser rear spar is also partially attached with some of these rivnuts, that will be temporarily installed then too.