Proof Marks : Proof 1 Proof 2 Proof 3 Proof 4 Proof 5 Proof 6

49, 50, & 51. German proofs found with proofs 42 or 48. Indicates the weapons were a contract purchase by certain units such as police or postal departments. Similar proofs are noted on the matching magazine.
52. Receiver proof found on SOME Mauser manufactured Dutch contract Lugers.
53. Austrian "Bundes Heer" (Federal Army) proof.
54. Krieghoff proofs, 1935-1939. The right proof is found on all parts.
55. Krieghoff proofs, 1939-1945. The right proof is found on all parts.
56. Krieghoff proof found on the receiver of the commercial "Side Frame Inscription" variation.
57. Krieghoff commercial proof found on "late" commercials.
58. "Ku" proof. Found on receiver, barrel and breech block. Receiver serial has "Ku" before or after number. (Most examples also have Mauser military proofing).
59. Krieghoff proofs found on the frame of some post war assembled weapons.

Courtesy of Ted