The guy's in the Northwest ran into this situation shortly after they invented Clown Racing.
I have come to the conclusion that there were at least two versions of the PDF flying Clown produced, possibly more. Some guys actually built their models from original kits, only to find that their models were different from others said to be built from original kits. So, there's a good probability that there was more than one kitted version.
Racers being racers, some of the Clown Race airplanes that showed up at contests hardly represented the original in some areas. This prompted one of the racing event organizers in the Northwest to build an airplane incorporating what he felt were the best versions of wing, fuse, and tail section from plans of all the versions of Clown airplanes he could source, and brought the model to the Northwest Regionals for several years during the events infancy. He basically said "If your model looks like this one, it's not legal".
This was to prevent the usual crossbreeding that racers sometimes find advantageous.
I have a drawing, along with a note, that came from a fellow in the Jersey area named Hilary Kahn. The note confirms the drawing to be a true reproduction of an actual PDF Flying Clown kit. Since my airplane is built from that drawing, I carry along the plan and note to every contest I attend. Just in case...
BTW, a true PDF Flying Clown airplane, never had wing spars.
Les