Spent a lot of time figuring out how to get the filler ring to pull up on the leading edge skin. The threaded tube welded into the tank was a couple of degrees out. End up putting several layers of cork stips radiating away from the hole. This put pressure on the tank top when the skin was in place. Worked just fine. I hope when the tank is filled it doesn't push too hard on the top of the tank/leading edge skin.
