Looks similar to the Long EZ John Denver was flying.
Thats about where the similarities end. Thr long ez is built from foam cut to shape and covered in glass. This is a moulded air craft using mainly carbon fiber. Ronneberg, worked with/ for rutan, for years.
John denver did die in a long ez. One where the fuel selector swtich was install behind the pilot fmso that thr passenger could work it. It was also mislabled( backwards iiirc) the offical report from the faa said that after running out of fuel, he tried to reach the lever and gabe a right rudder imput. There was some other things like you had to use a mirror on a stick to even see the gauge. Sad deal.
Preduction ened in 2002 amd the lady that ultimately owned the design died in 2009. No one has a complete plan set with lofting and lay ups. If those were to exhist you could produce a plug and a mould. You could theoretically reverse engineer it from an actual air craft( there were 30 something registered). It is possible to build a plug, then mould and rengineer the lay up.
Modern 3d maping and cnc technology, could rough out a foam in 1000s of man hours less then it would take by measurements amd hand carving. Still easily 1000 man hours and 50-10k in maping/ cnc and supplies.