I don’t want to be the weirdo on this, but what the heck. In the event that the OP has not fully thought this through, and he probably has, but just in case.........it seems counterproductive to me to so this for a whole host of reasons.
You can get one perfectly nice Contax G1 body, almost two for the $500 DAG apparently charges to convert one lens. Which allows you entry into the entire stable of lenses and not just one. And for less money. And still leaves you with the option of even more of that excellent G glass, not just one lens.
I could understand this if we were talking about converting one favorite lens for use on a digital M, but if you are just going to use it on a film body, there are cheap Contax bodies available that take better advantage of the lens than an M4P will ever be able to. The G1 gives you autofocus. Metered. Auto exposure. And the autofocus works regardless of what some say. That’s an issue with them, not the camera. The G1 will allow you to focus down to 0.3meters. Plus, there are advantages to carrying two bodies instead of one. Two speeds of film. Color and b&w. I know, one body is smaller to carry than two, so there’s that.
Anyway maybe you have already considered all that and still decided to fo the adapter route, and that’s fine. Just a thought.
I adapt all kinds of lenses to all kinds of cameras, but not going to adapt G lenses to my M. That just seems like a case of one step forward, two steps back to me, as one who uses both cameras and both types of lenses. But, whatever works best for you is best for you.