Who made this Jordan 1742 Long Land, and where could I find a barrel?

[TFoley]

Here's the inside of the lock, what am I looking for as to the boss for the front bolt?

As to the legalities, it was on auction in England as it is. The auctioneer informed me that the barrel no longer exists. Whatever happened to the barrel, and why, are closed books.

I know the British law, but many in Britain, including heirs, police departments, auction houses, and some R.F.D.s do not. And some who do choose not to jump through the hoops.

You did not mention that. As the BB and its ilk are smoothbore, it would have been subject to Section 2 of the FA. It's more likely that somebody just wanted a good barrel for their replica.