If I recall.. Bethwaite had wing emulating wooden mast on his 1970s world title cherubs. Werent wings but a D shape... Construction methodology may be found in his book or online perhaps in the Cherub webpages.. Suggest the UK one before the Au ones.. I do recall them being stripped so perhaps western red cedar and a white pine?

The issue was they were so stiff for and aft they had to have slots cut into the front to allow them to bend. Worked well but eventually the slotted areas just popped out..

ps one can get aero-grade ply in 1mm!!