haha - shows how long it's been since I flew a piston single! I was actually thinking about it before I wrote it, and thought that it should have been the right rudder, however I seemed to remember my left foot doing most of the work, so I went with my heart, not my head.
yxcapt, for a balanced, level left turn while inverted (that is left as the pilot sees it, not a following upright aircraft) you use right stick, forward pressure and left rudder to co-ordinate.