this P.38 was made in 1944. The serial # is 4xxx l. The l is a suffix to the serial #. The Germans in WWII had a serial number system. They made 10,000 pistols in blocks with a letter suffix. There was an a, b, c, d,soforth. Your pistol is the 4,xxx pistol made in the l block in 1944. There are exceptions such as no suffix, some prefixs, 0 series, etc. They did not produce pistols in the i block due to the i looking so much like the j. The serial # is repeated four times on each pistol (one on left side of slide, one on left side of frame, one on the barrel at front can be seen by looking underneath barrel, and once on the locking block wth only last three digits of the serial number with the suffix). If it is a two digit serial number such as 56 a then only 56 a will be stamped on the locking block. Also the AC in front of the serial # on the slide is a code for Walther. Mauser made P.38's and they used byf code. Spreewerk made P.38's and their code was cyq.