Are you talking about the Dura Sight (Z2) Alloy Scope Mount's High & Low base from CVA? If so I purchased a set of the High-Base for oneof My ACCURA's last Christmas and did'nt try them untill this Fall when I went to sight in for the first time. The Quality is good, but they did'nt work well on My ACCURA, they fit fine and I had just enough room to pull the hammer back with the see-thru's. But when I went to look through the scope the mounts were just a tad bit high and I had to raise my head to an uncomfortable position to be able to see correctly. They may work well on other ML's but they did'nt for me as I still have them brand new and may not ever use them. Im sure the Low-Base would have not worked either giving me the room I needed to pull back the Hammer. Also with the Low-Base you'd have to remove the rear sight to mount the scope.
(BP)