It's the drawing of the Ed Horkey's "Twin Mustang Racer" (1995). Project for the world speedest props plane. Horkey was about the builders of the P-51 Mustang. The plane was foreseen to have 75% of the F-82 "Twin Mustang" size.
I found this in "Die schnellsten Propellerflugzeuge der welt", Ferdinand C.W. Käsmann, Aviatic Verlag, 1996.