It's nice to finally be building again after a move. I picked this older kit up from Wheels & Wings in Toronto.
The actual car was a factory prototype that was sold off in 1956. It was dismantled and stored for 30+ years and has since undergone a total restoration.
Multiple methods failed to replicate an acceptable aero tonneau cover. I used the Juanjo Mas technique of multiple strips to create the correct shape. The short door lines are filled with stretched sprue.
A heavy primer coat and a wet sand should yield a nice smooth panel.
I will massage the tonneau a bit prior to cutting the cockpit opening.
The belly pan and fender skirts are in process too.
The Tamiya Porsche 956 and Hasegawa/Revell Porsche 962 have flat fans. Conical fans are in the Revell/Monogram Motorsport Mustang, Tamiya Zakspeed Capri and the new Beemax 935 K2. I don't know of a specific AM source.