Just look at the insides of the thing; I assume the dotted bits were carved from balsa blocks and just look at that wing which appears to have four(!) spars, no ribs, and those angled veneer laminations for the skin. IIRC the Mosquito had a similar wing.
very nice design, it's new for me too!
My plane will look like this one, but fixed gear, no diheral and bird cage canopy. make me exited to discover this beautiful plane ..flying.
inspire me for the paint scheme( red with white strip)
deHavilland TK 4's construction has been used on several recent home built a, albeit updated with modern materials. Filling a tiny airframe with balsa wood or foam vastly reduced the thousands of cuddly little bits to a handful of blocks. Below a certain size, balsa or foam filler is the cheapest and lightest way to build wings.
Most of Burt Rutan's mood-less composite airplanes are filled with foam and covered in composites.
Cri-Cri glues aluminium skins over foam cores.
Impractical and feasible to home-build would be a somewhat narrower category -- it removes, say, the X-15 -- but does allow some exploration of the weirdness of aviation history, like these: (Gallaudet D-4) (Burgess-Dunne D-8) (Fouga CM.88)