I like the plan Peter, a little bit different, so I am looking forward to it as my winter build. I have a new OS 30 4S lurking in my shed looking for a home and wondered if it might be suitable for the Luciole? A little heavier than the 21 you used but then the design needed three Oz of lead in the nose for the C of G. Would the front end need a little beefing with the four stroke? I am considerind an electric alternative which might work with the right motor/battery combo. Decisions, decisions!