VERY nice and very restorable!
DP markings could be stamped on rifles for a variety of reason and did NOT necessarily mean that the rifle was unfit for use. The problem was that the DP stampings were hard to remove so, often, a DP rifle could be repaired to get rid of the DP status.... but still be DP marked.
This one has definitely seen combat use in the Great War: it had a new barrel pactically just last week (actually 1916)! Many of the chamber markings are proofmarks telling you that the rifle was tested for a cartridge case length of 2.222", a working pressure of 18.5 Imperial long tons per square inch (41,440 psi).
The butt marking disc alone is enough to give heart failure to some advanced collectors I know: May, 1935, Royal Air Force, No. 6 Fighter Squadron (I think). This would make it a Battle of France rifle also, would it not? No matter, anyway: it makes the rifle TRACEABLE to its Service career.
There will be an "HV" marking at the rear end of the back sight: "High Velocity" meaning that the sights are set for the 2440 ft/sec velocity of the Mark VII Ball round with the 174-grain composite flatbase bullet.
If you need in-depth information on just how to restore this little prize, scoot on over to milsurps dot com, take out a (free) membership and start pillaging their Military Knowledge Library. They offer every manual you will ever need, all free for the downloading. Read the forum threads carefully, too: they even have three working Armourers who specialise in these critters, not to mention a few other folks who do know what they are talking about and who work on these things regularly.
A FINE toy!
Good luck!
And be sure you keep us posted here on "the rest of the story".
