Cor, you're keen.
Here's some more info:
Adaptor pin / sleeve, as per Martin's diagram (10mm OD, 8mm ID, 2mm 45deg chamfer, 20mm overall length)
Casting number on the cylinder. No idea if it's of any use
Pic of the stepped nature of the servo end of the master cylinder. The larger portion is 40.5mm in diameter, the smaller 36.3mm in diameter. It's the larger of the two steps that creates the seal between the servo and the cylinder. The mounting holes are 8.5mm diameter, and have PCD of 70mm
The cylinder from the end looking back, showing the layout of the high pressure brake hoses (stainless) and the low pressure feeds. The studs are at 25 degrees from the vertical
Do you need anything else?