Track of the wolf sells a breech plug for the cherokee's But I know of no one who makes a breeched barrel for them. You could get a breech plug and fit any barrel to it. Which is what I did for the cherokee I bought with a bad bore. :idunno: Oops I did not notice that this is on the flintlock forum, mine was a percusion.!
Not AFAIK, but IMHO one would make a purdy conversion - IIRC, there was a thread a few years ago, about altering a T/C caplock patent breech to rocklock, complete w/pics.