I've asked Mike Eagleshield about this. According to him, the parts will all go into the frame. Its just a matter, as he puts it, of jacking the gun up, and rolling a new gun in underneath it. He couldn't quote a price on the conversion because we weren't talking in formal capacity (hell, it was at a cigar party), and he didn't have the numbers in front of him, but he confirmed that it could be done, that he himself had done it. I get the impression that the easiest and cheapest way to go about this would be to find a good deal on a beat to hell 75B, and switch the parts out. Then you'd have your manual safety P01, and a decocker 75B that you could either sell or keep as a pack gun, car gun, whatever.
With the P07 coming out I see it as being less and less of a practical idea though.