It is the Mini Mauser / Mark X / Interarms / Charles Daly / Rem 799 trigger. Midway lists them but they have been on backorder a while. Timney does not even show them on their own site, but call them up and they might get you one. They found one for me (cheaper than Midway). It is quite nice. My only complaint is the safety is not real positive feeling from off to on, but the trigger is crisp and adjusted down nicely.
I "think" the difference is the height, the mini Mauser is shorter for shoe to trigger guard clearance.