I spent all day drawing the flaps in CAD. I just couldn’t wrap my head around it.  The 3-view, and the panel lines on the plastic model, had me completely stumped. Since, I do not have a photo of the top side of the lower wing, I could not confirm it, and nothing seemed to match. I have literally drawn every type of aileron, flap and hinge combination in the book, including Friese types. The only 3-view showing the flaps correctly, is the ugly coloured one from Germany.

Anyway, I got there in the end.