E.M. Reilly 28-bore hammer gun, snap underlever.
This seems an unusual one. 28 bore in a single shot hammer gun.
I seem to remember Charles Fergus having a Reilly gun*. I could be wrong. He used to write good wingshooting books. It looks like he is still writing but I have seen anything for years.
*Nope. I checked his books. He had a Rosson they traded 12 or so to end up with 2 Jeffreys.
As usual, open in new tabs for big pix. Twice for small ones.
Would like to buy the 28ga. I have one E. M. Reilly.
https://www.vintageguns.co.uk/
FYI That is a 3 year old post. The gun was being sold by the above.