You've likely found that Claude Bowes-Lyon, 14th Earl of Strathmore and Kinghorne, was the father of Lady Elizabeth Bowes-Lyon, the future Queen Mother. Here with her father, and her eldest brother, Patrick. Claude lived 1855 - 1944 so it may have been his gun. The history is fun but without provenance adds nothing to the value of the gun.
![[Linked Image from photos.smugmug.com]](https://photos.smugmug.com/Shooters/Historic-Shooters/i-nqJQWCG/0/K7WPpCXP4FP9sLDXz4tkCxgj7nJCDdQnbBC4DnSsW/L/Lady%20Elizabeth%20Bowes-Lyon%20with%20her%20father%2C%20Claude%20Bowes-Lyon%2C%2014th%20Earl%20of%20Strathmore%20and%20Kinghorne%20%2C%20and%20her%20eldest%20brother%2C%20Patrick-L.png)
Earl and Countess of Strathmore with the Duke of York (after 1932 King George VI) and their daughter, Elizabeth c. 1922
![[Linked Image from photos.smugmug.com]](https://photos.smugmug.com/Shooters/Historic-Shooters/i-68P8hZ3/0/KKNkG6x28XdFShGDTVrzGTNTHJRjM94bpCtQN4H5Z/M/Earl%20and%20Countess%20of%20Strathmore%20with%20the%20Duke%20of%20York%20-%20King%20George%20VI%20%281932%29%20and%20their%20daughter%2C%20Elizabeth%2C%20c1922.-M.jpg)
The proof marks date to 1875 - 1887. Both bore and muzzle are 12, but it is marked as CHOKE (usually NOT FOR BALL). It's possible the bore could be up to .750" (11 is .751) with muzzle .729". Fractions were not used until post-1887.
It looks to be a utility grade gun but has better 3 iron crolle damascus. 3 sets of initials on the bottom rib. CH & ?GW could have been the barrel maker or fitter.
![[Linked Image from photos.smugmug.com]](https://photos.smugmug.com/Shooters/Historic-Shooters/i-n7ht3qH/0/K8mcHNr6LpJDcrCxBvdsg54vgZM3pV39VNHzMGrVJ/M/JP%20Clabrough%2075%20-%2087-M.jpg)
With the screw in the head of the stock it's probably a wall hanger.
Here's a higher grade Clabrough hammer gun of similar era that sold for little money
https://bid.circle-auction.com/onli...ros-london-double-barrel-shotgun-5157899