Stephan, thanks for this thread, and your images
(credit: two photos, and write up, and schematic, are from the Cobra-Ferrari Wars 1963-1965, by Michael L. Shoen)
my copy published 1990, American edition.
First the schematic from the book, better resolution than what Dave posted, but is Dave's in post 3 an original ? and this one a later
drawing by L. Honneger ?
I can post a larger scan if you guys want it.