I seen these side by side rails that mount to the front site aka triple frame of a MP5 at http://www.a2zoutdoors.com/h&k_mp_5_accessories.htm I would like to mount one of these on my V51 pistol I'm building. I will be using a triple frame from a G3 kit. My question is. Are the tops of the G3 and MP5 triple frame the same? I don't have a MP5 to compare to.