LATE 1880s FRETLESS 7 STRING, MAKERS MARK?

[IAN SALTER]

I appreciate that it's highly unlikely, but has anyone ever come across the stamp BB on any banjo? I've just bought this one, that has that mark and the number 510, on the underside of the perch pole.

https://i.ebayimg.com/images/g/8ikAAOSwPwVnpg0P/s-l960.webp

https://i.ebayimg.com/images/g/mgEAAOSwu9Jnpg0Q/s-l960.webp