First of all, Welcome to THR.
The first thing I'd do in your position is buy a Dixie Gun Works catalog. The most entertainment and practical info on All Things BP you'll find for $5 anywhere.
They'll have all sorts of components, info and paraphernalia to make paper cartridges for your Sharps in there. FWIW, I understand that there's someone out there who makes and sells cardboard tubes sized and intended to make cartridges for the percussion Sharps rifles and carbines that are supposed to eliminate a goodly amount of the tedium associated with producing ammo for these arms. Holt Bodinson mentioned them in an article in his "The Surplus Locker" column in "Guns" magazine last year about the repros of military and sporting percussion Sharps rifles. He also listed sources for precast bullets, moulds and assorted other goodies as well as some loading data. You could probably find it in the archives at their website.
Congrats on the extremely nifty carbine!