I am working on rebuilding a 42 MB. The frame is a disaster. A previous owner cut the frame off after the shackle mounts. Can an MB owners measure the distance from the back of the shackle mount to the end of the frame in the rear where it meets the rear crossmember. As a double check, also measure from the machine gun mount crossmember to the rear end of frame. I need these measurements to correctly place a new A-Frame member and the rear crossmember. Much Thanks