Quick update - another mini project within this project!
I was originally planning on using a good quality GL1000 master cylinder for my project, however...
The original CR750 master cylinder was a different part than any street models, it had an angled reservoir and a bigger bore/output to handle the twin disk set-up.
It is hard to see in the ACU homologation files, and from this image of the late Tommy Robb:


I managed to borrow a genuine CR750 master cylinder for a few days (magnesium), 3D scanned this and have started the process of reverse engineering it. The cap is slightly different as well! I will likely use genuine GL1000 valving within the custom body, so that it can be rebuilt if needed in the future.
3D Scan results:


The CAD progress so far:


Cheers,
CR21