Well, seems to me your doinf quite well already?? Nice!! However, I know what you mean. What I would do in this case is use the cloning tool and kind of clone my way around the areas where the hands are attached to the 2D image. It should appear as if the hands are actually "growing" out from the image so if you mix the 2D pixels with the 3D pixels you well get that result. You may also wish to use good old pixel by pixel rendering, (I know this can take a long time, phew) but this will give you a nicer end result. Then if you need to, use the blur mildly afterwards. Hope this helps?? ;-)