One other note about modifying the stock K45 mount for the X-45, besides enlarging the pocket length, my photo doesn't show the extra notches I needed to make to clear the X-45 strap screw heads, you need to notch the aluminum for the screw heads to clear as the X-45 fits up close to the mounting rails.
The stock drilled an tapped holes for the K 45 will work but you need to elongate the holes on the X-45 straps very slightly.