Daryl, I'm pretty sure V-C makes their own barrels now, or at least that's what their catalog indicates. Not sure that's always been the case.

Interesting stuff on the V-C sliding breech gun.

DR was likely the actioner of your gun, DT--although the initials don't ring any bells with me.

James, looks like your gun started life as 2 1/2" and was at some point lengthened to 2 3/4".