Dean is on the wrong side of the channel but close
They are "Fine (3 Iron) Laminated Steel" sourced in Birmingham.
The Parker "Fine Laminated" offered on Quality I and H hammer guns in the 1890s catalogs is a grade below the "Fine Damascus" used on Quality G, and referred to as Lam1 in the Parker stock books. The 1888 Colt Patent Firearms catalog also has a quality gradation from Twist to "Laminated" to Damascus, and Hunter Arms used "Laminated Steel" on Quality No. 1 L.C. Smith guns 1892-1898, and some tubes also have Birmingham proofmarks.
This is Belgian "Pointille" Laminated Steel; 1890 12g Grade 1 courtesy of Milt Fitterman
Dean posted this some time ago. 1899 PH Laminated Steel barrels, rib marked 'Damascus Steel', and 'T' stamp on flats. Can't tell if it's the same stuff
I added a couple of the images here, with an attribution Paul
http://www.picturetrail.com/sfx/album/view/17227428