Bigpines, Eric and RT are exactly right, it is not the window size that is restrictive, it is the inward angle of the window. The door skin is about 90 degrees to the ground plane where the window is about 45 degrees. When the window goes down, it goes out about an equal amount, quickly hitting the door skin.
RT, thank you and I too am a big fan of butterfly doors. Fran at RCR did a great deal of developmental work on a spherical hinge that he uses on his SuperLite Coupe. He has offered his technical assistance and parts on this project. If you look at the side view, particularly the back top of the door above the Naca duct, and picture a Lambo door motion, you will see why I too am interested in this solution.
Eddie, thank you for your additional images but everyone realize that those were published by Flavio before our association and you will never see an image from me that says Lambo on it.
Digibeam, although the wheelbase, track, and other specs are Countach (with the exception of a 1" taller roof), it was Flavio's original idea to offer an electric concept. I should have made it more clear in my answer to Notnilc20 that this is the final design for the taillights, below them there are dual stainless Magnaflow mufflers in the conventional version. I can still do a rear skirt like that if you pursue an electric version.
LP670Mike, did you think that you would get 36 responses to a simple question about a Countach body? Pics are coming.