producerxtr,
Sorry, it simply does not work like that.
Do you really imagine that Sony could charge 11K or whatever they want, for a microphone that someone like you - albeit with access to CAD/CAM - could copy based on public information?
Converting something like the C800G into a viable DIY-project would take a hell of a lot of time and effort - and would require a deep understanding of what actually goes on in there, mechanically, acoustically and electronically. And no, nobody did the work for you already - which you would have known if you searched first. Probably because it's still in production, and copying current designs is considered no-go - if you want, you just buy.
If you're interested in digging deep into this, you could try to have the japanese article on the subject (from my webpage) translated to english - maybe there's some extra info hidden in there.
But don't expect this to get anywhere without a lot of work on your behalf - and then possibly only when Sony eventually decides to discontinue..
Jakob E.