Recent posts indicate that although the Crane XR700 ignition kit is still available, the new kits that come from FAST (who took over the line from Crane Cams) are not offered for the Jaguar V12 and therefore do not include a12-slot shutter disk. Some have suggested that one could be possible be made using 3-D printing or other technology. Since I have mine apart to replace the optical trigger, I took some photos and measurements:
The parts are laying on grid paper with 1" major markings, 1/8" minor markings.
Here’s another photo at a slightly different alignment with the grid:
Although I don’t believe it’s critical, the hub mounting hole that is approximately opposite to the key is about 19.8 degrees away from the bottom disk slot.
The disk is 3.70" in diameter. There are 12 equally spaced slots, 0.052" wide and 0.180" deep, measured from end radius to outer edge of the disk.
The 3 holes for attachment to the plastic hub are 0.137" diameter. They are equally spaced and measurement between the outer hole edges is 1.355" (i.e., center to center is 1.355 - 0.137). I didn’t do the math to find the radius, but that should be easy enough.
I didn’t measure the 3 large slots, but the approximate dimensions can be read from the grid paper. The purpose of these slots is to allow access to Allen head cap screws that fix the distributor base to the engine top cover, so exact dimensions are not critical.
Hope this helps someone to take on the project.