OK you asked so here I made som explanations in Paint using your image. I hope you can use the info.
Just ask if there's something else. I can take a couple of pics on some of the parts.
Some were laser cut here and some NOS from Modena.
However, I can not sell any of them as they are for use in my F-cars.
The cover between engine to cockpit have more angles than in your 3D. Pic will follow later.
The cover between the seats is straight with only a lower angle to cover the shifter shaft.
Drawings are in the F40 manual and Ferrari Story magazine that feature the F40 but none are complete.
You can also find the cockpit rollbar details in the FIA homologation papers.
A friend of a friend that I could visit to get measurements from sold his F40 a few years ago.
I only forgot to get the angled seat positions and shape of upper steering column bracket.
After asking around I have so far only been flipped off by other people who have access to an F40.
If they ask me for anything later, I know nothing... capisce?