A previous post indicated that the issue of "markings" would at some point be considered. I have been studying the firm of William Powell & Son for some years and can offer some observations on their practices.

In 1886, the editor of Shooting (a periodical of the gun trade) sent a letter to gunmakers asking how their ribs and locks were marked. The results were published in the 9 March 1887 issue. The response of William Powell dated 5 October 1886 was published and it read "Sir,- In reply to your enquiry, we have to inform you that the barrels of our guns are named "William Powell and Son, 13, Carr's-lane, Birmingham," and on the locks William Powell and Son." His response raises a number of issues. First (excuse me if I seem a bit pedantic) Powell's signature uses an ampersand (&) not an "and." I have never seen a dash between Carr's and lane and "Lane is always capitalized. Now to more substantive concerns.

During the period of 1870 to 1890, the highest grade of Powell's patent action guns seemed to have been made for clients such as W. Richards, Williams & Powell and Barrett.
The ribs and locks on those guns were marked with the client firm's name.

Lower grade guns destined for America and South Africa were marked in a wide variety of ways. Those markings were frequently detailed in the day books.

Finally, in my collection is No.8476, a lever-over-guard 12-bore that was sold on 17 October 1887. The rib and locks are marked only "Powell."

This information isn't meant to denigrate Powell as I am as passionate about that company as Argo44 is about Reilly. Rather, it is a caution that likely applies more broadly to the entire Birmingham gun trade.