Lefty's gonna be tough, especially in those cal. There are so few lefties made and enough lefty shooters that most barrels are still being used, my son shoot's left,(cross dominate). I think CVA made a few but are rare.
Your looking at custom components for around 200-225 then labor too assemble. Or a gunsmith with knowledge of BP rifles could swap the drum breech to the left side on an existing barrel for around 100 if ya find the right guy, most gunsmiths are gonna be nervous about pressure issuse's.
Call, Deer Creek Products ( no web site) that's where we got Dustins Traditions lefty, 765:525:6181 they have all the Traditions and CVA stuff ya could possibly hope for.