Indeed a great looking old Clabrough. My Clabrough is marked J P Clabrough & Bros & is from the 1890s @ SN 4230. It has 28" Damascus barrels, choke in both barrels. It has 2 5/8" chambers & a Doll's Head rather than a Cross Bolt. Hardly any finish left, either case colors or bluing, but with low pressure 1 oz loads it is one fine quail, woodcock etc gun.
I have seen some of the history of these guns but forget now just when Johnson became a part of the company. As I recall he was the US importer in California.
In Lawrence P. Shelton's book, J.P. Clabrough Birmingham Gunmaker it states that, "Douglas Vaughan Johnstone owned the Clabrough Company in England from 1892 to 1918."
Interestingly, big changes came in 1914 for Clabrough & Johnstone. Specifically, in 1911 the gun-making firms of Isaac Hollis & Son and Bentley and Playfair had amalgamated and following in 1914 Clabrough & Johnstone also amalgamated into the same group, all of which were headed up by Douglas V. Johnstone. From 1914 on-wards, they shared the same premises and workmen in Birmingham. So my Clabrough & Johnstone shotgun would have likely been built in 1925 by the Hollis, Bentley and Playfair firm, even though it's branded Clabrough & Johnstone.
The book also states that Douglas V. Johnstone did have a son named Philip Douglas Johnstone who immigrated to the U.S.A. in 1925, being listed as a gun-maker; he apparently worked for Griffin and Howe in New York City, and died in 1989.
Edit: See the attached article J.P. Clabrough, and the California connection.
J.P. Clabrough Article 
