Good question, I'd asked the on here a good while back and Bushveld replied.....
"Frank Lilly, Henry Lilly and JACK LILLY were three generations of barrel filers in Birmingham."
I'm not near my books at the mo but will have a look if there's info on how many of the family were in the trade. I think the gun I have with the stamp on is from around 1900 so that may help narrow it down.

Rust never sleeps !