Yeah go for it Jon. If you need to know the gap angles, chord lengths, arc lengths etc drop me a line.
The ring made up in ally with laser cut numbers would look awesome! and there's certainly plenty of people who would want one (depending on how pricey they are).
I'm still going to go ahead with the 3D printed version though.. the idea behind the 3D model is that once I've got it and I know it works, then this 3D printing lark is only going to get better and better in years to come. So in 10 years time I'll still be able to find a 3D printing company, send them over my design and get them to make something exactly the same as one made today (only even better quality by then).