I have a Remington Rolling Block with a HV contour barrel with Unertl style mounts. I want to switch to a Picatinny Rail which would be mounted on the barrel and have a cantilevered extension of several inches to the rear. The cantilevered part of the rail need to be milled to a thinner section to clear the receiver (1/8") and the total length can be as long as I want. The bottom of the rail needs to be milled concave to sit down on the barrel without rocking. Should I just by a 1/2" blank rail and have my gunsmith go from there or is there already one that is partially meeting these specifications? Hole spacing is not too critical as the barrel will need to be drilled and tapped anyway. Thanks for any ideas. Tom