PPK-L
In the 1950s, Walther produced the PPK-L which was a light-weight variant of the PPK. The PPK-L differed from the standard, all steel PPK in that it had an aluminium alloy frame. These were only chambered in 7.65mm Browning (.32 ACP) and .22 LR because of the increase in felt recoil from the lighter weight of the gun. All other features of the postwar production PPK/S (brown plastic grips with Walther banner, high polished blue finish, lanyard loop, loaded chamber indicator, 7+1 magazine capacity and overall length) were the same on the PPK-L. In the 1960s, Walther began stamping "Made in West Germany" on the frame of the pistol right below the magazine release button. The 1950s production pistols had the date of manufacture, designated as 'month/year', stamped on the right side of the slide. Starting in the 1960s, the production date, designated by the last two digits of the year, was stamped on the exposed part of the barrel which could be seen in the ejection port.
Read more about this topic: Walther PP