I think Captchee covered it, yes the locks and barrels interchange. As to location of the vent, that varies in factory built guns, most T/Cs have the vent off-center of the pan, either to the front or rear. People say it does no harm but i just wonder why T/C can't get them centered, other makers seem to have no problem. I agree with Captchee that for the cost of a new barrel and lock you could probably find a used rifle, most pawn shops have at least a couple of T/Cs but most used muzzleloaders I have examined have had bores damaged by rust and or rings from firing with a maxi-ball not fully seated. I would suggest you get one of the Green Mountain drop in barrels, they are generally much better patched ball shooters than is the T/C barrel, offer a variety of calibers and cost about the same. For that matter, L & R locks offer a replacement flint lock for the T/C which also costs about the same or less than a factory T/C lock and most people find the RPL locks to be an improvement over the T/C. Check out
www.trackofthewolf.com for those items and thousands of others with very good photos of everything they sell.