Tom, New Orleans guns are primo collectibles. You might want to think twice about stripping the parts from the old wood and going to an old/new remake. For the sake of the gun, it would make just as much sense to consider mending and restoring the stock where needed and finding a set of locks for it. The missing parts are out there, it just takes some time to hunt them down. You would end up with a neat old double gun with a down River history, even though it is an imported gun. The N.O. markings make it such. Not sure that I have ever seen a fully American made shotgun from the 1800s even though some were surely made here.
Dick