Will set up a threaded rod in the lathe to form a cone. Have taken measures of if from a photo I got from Andrew.
Actually tried my concept with the 5.5 with original rig last summer. We then used 115cm wide and low foldable wings, that lifted to leeward when sailing.
The wings where great but we felt wider beams(320cm) and narrower wings(80cm) was the solution, resulting in a width reduction of 10 cm, although righting moment gets a little higher. Might go down to 305cm if things gets boring.
The new higher F18 rig will give slightly more heeling moment. Will also experiment with a slightly bigger jib made from a cut down 49er jib, going lower to the rails. If this isn´t enough I also have a Marstrom Tornado alu rig lying around.