The marks relate to the 1925 Rules of Proof. The 1 1/8th. ounce service charge denotes it has 2 1/2" chambers. They started putting chamber length on after 1954. I suggest you use only European ammunition that has the CIP mark on the box with 65mm. or 67.5mm. length cartridges. I know the 67.5 is longer than 2 1/2" but they are o.k. for that chamber length. The U.S. does not have comparible proof standards on either guns or cartridges and U.S. 2 3/4" stuff is generally a lot hotter as to pressure than European stuff. Please don't strain the old girl!
Midland guns are quite interesting in that a great many were as per the catalogue; although they did make one offs to order, if you can show a picture of the side of the action and let me know the type of fastening to the action and the forend I may be able to say what it is. They had very fanciful names for their guns. Sadly no records exsist. Lagopus.....
