To be honest the ship is over most of our heads at SM. It's a tough ship to figure out. What looks promising is that there was a macquete made for the movie that appears in the making-of book. You should check it out.
Hmmm... where are you located and is this something you are willing to put the time and effort into completing if I do the CG model of it? I can definately model the ship... but I've never modeled anything that would ultimately be used to CNC parts so, I'm not sure if it's as simple as providing a 3D mesh and letting the CNC just go at it.
If you are really interested in trying to CNC the Serenity, contact me via e-mail: dijinn(a)hotmail.com
I've been 3D modeling for 5+ years now and the only thing that would limit me is getting references to accurately model the Serenity. I'm a HUGE fan of the show and would love to see an accurate kit being offered.
It went the other way. They used the CGI to make the practical model. To what purpose they did so is anybody's guess. Look in the Serenity Movie Book and you will see the "grown" un-painted model in it.