If the coupler box is part of the body, or frame, there might not be a simple MT conversion. Accumates, from Atlas, should work, But the MT couplers need motches in the top and bottom of the box, for the pins on the shank, and Athearn usually doesn't provide those. Atlas does on their cars and locos, so they can easily be converted to MT, usually 1015s
If that's the case here, the simplest solution might be to find an Atlas car with body-mount Accumate couplers, put 1015s on it, and put the Accumates on your loco.
If Athearn has started making their locos MT-compatible, I will thank them.
