It’s a [plate] stock lock (as distinct from the Banbury stock lock which has no metal backplate). They were commercially made in Willenhall 18-20C. Most locksmiths were small businesses in a shop behind the house, employing 1-2 men and 1-2 boys; there were over 200 in Willenhall and one such workshop (a nailmaker’s) still exists.
Your lock appears of good quality - the bulleted extra plate on the keyhole. And earlier, probably 18C; later, the wedge-shaped backplate became parrallel-sided, then the end became rounded. However, the wood stock looks likely to be a later replacement, which is not unknown.
Such locks were also made by local blacksmiths, but many were exported to the Colonies. Any cheap offcuts of wood could also be used - even scraps of expensive mahogony; but oak and elm were more usual. Later ones used softwoods.
