Alvin,
Imperial DWM and Erfurt Lugers 1912-1918 were stamped with three inspection stamps and one proof eagle on the right receier, in accordance with the Army marking instructions of 1910 (amended through 1914).
The leftmost stamp was applied first, certifying hardness of the receiver and stamping of the date stamp.
The second-from-left stamp was applied second, certifying the pistol's assembly and its readiness for power proofing and shooting-in.
The pistol was then power-proofed, and the rightmost proof eagle was applied, certifying proof. The barrel and breechblock were stamped with the proof eagle at this time, also.
The last stamp, between the assembly stamp and power proof, was applied last, certifying Army acceptance of the firearm.
DWM First Issue P-08 were stamped on the left receiver with two inspection stamps and a proof eagle. 1910-1912 DWM, Erfurt P-08 1911-1912, and WWII Mauser P-08 were stamped with two inspection stamps and proof eagle. Though it is by no means certain, these
probably certified assembly and acceptance, leaving out the receiver hardening/date certification. Imperial Navy Lugers were stamped similarly, with two crown/M inspection stamps and a crown power proof on the left receiver.
Simson Lugers were stamped with the full suite of four stamps, following the 1910 marking instructions.
--Dwight
DWM Imperial Navy Lugers w