Actually they do make them, well I do anyway LOL

Take a look at this page, and then the link to all the parts below it:
http://www.extremerc.com.au/estore/i...th=146_266_319
http://www.extremerc.com.au/estore/i...;cPath=146_266
My adapters run pretty true

I start with a german blank and then finish it to suit the CS10 and now CS12 rotors.