You can download application and Cert.of Compliance from www.titleii.com. It costs $30/3 years. Send copy of application to your CLEO. You do not need his approval or signature, though.
Check out Century Arms and Southern Ohio Guns, AIM Surplus, etc. Send a copy of your C&R to Midway, Brownells, too and they give a discount.
Most of these places will denote which guns are C&R, you have to send them a signed copy of your C&R (don't sign the original, just the copies). Don't know about Cali regarding shipping to you.
C&R opens up a whole new world: less regulation , less hassle, less cost, more fun!
My C&Rs: K-31 Swiss, Russian capture Erfurt K98k carbine. Delivered to my doorstep.
As far as I know you can change the configuration to anything legal, including a custom.