You might consider the left hand Bailes lock in L&R in prcussion. I have one for a future project. Us leftys have a smaller selection. The L&R would be a better fit on a smaller barrel. Any prejudice against a L&R, especially in a percussion would be misplaced. If you are going to a heavier barrel then look at the Durs Egg percussion. Siler does make a left hand percussion in it large size. There is no small Siler left handed lock, much to my dismay as I would love to have one.
DP