As as an interesting note, I'm a lefty and have owned and shot "right" handed toplevers exclusively, even though they may have been made with stocks for a lefty (or restocked). I've seen and handled a few mirror image left hand actioned guns. I've got to say that I believe that the right handed top lever is faster and easier for a lefty to open and load than a left handed action. To reload I push the toplever with my left thumb rather than draw it and this is a motion with less movement of the hand or the thumb.

FWIW,

JPK