Very hard to date, as noted already. Looks to me well-made, of the sort produced commercially by lockmakers in Willenhall. However, they were also made occasionally by local blacksmiths. Any offcuts of wood could be used, even mahogany! My guess is that the repair to the split in the stock is a later repair. I’m going to agree with late 18C - early 19C, but probably earlier rather than later.
There seems no known reason for the name Banbury, which was an area where furniture was made. The other sort of stock lock, btw, was sometimes distinguished as a plate stock lock. T C Crompton continued production of these until the late 1950’s in Britain.
