It's looking like if the prototype works out ok, I'll need to put in an order for about 20 of these things but I'll gauge definite interest once I've printed the prototype and posted up some photo's of the actual thing. Remember the real thing isn't going to look as good as the rendering in the first post so once you've seen the real thing you might not want one
I think I've corrected the gap distances now.. what I did was I cut the sticky part of a post-it note off and stuck them over my existing Nick Murphy ring, then transferred the marks to the post-it notes and measured the diameter of the ring at the point I put the post-it notes on.
Knowing the arc length and the diameter of the circle, I was able to accurately measure the gap sizes on the post-it's and transfer the correct angles / gap sizes over to the CAD model.
Then I produced a PDF of the ring at 1:1 scale, printed it out, cut out the ring carefully with a pair of scissors and fitted that around my real ring on the scope to make sure all the marks matched up exactly.
If you want to help and and try this for yourself, I've attached the PDF to this post - just print it (make sure you print the PDF to 100% scale), cut it out and put it around your scope to see if it matches up with the marks you've got on your scope.
That's what the gap sizes are going to be on the prototype for the imperial ring.