What you could probably do it have Luke or someone mill the rail to accept an AM/MM vert adapter. Essentially what they would do it mill the front lower edges so that the "wings" on the am/mm vert adapter will clear the rail. You could then slot mill the rail so that it will accept a single screw. Luke can do all of this as long as there is enough meat left on the rail. Otherwise check with Palmers Pursuit, they may make something that could be made to work. IIRC, they used to make an asa extender.