There is a molded calander stamp of the manufacture date, it looks kinda like a clock. These decode like this: A = 0 B = 1 C = 2 D = 3 E = 4 F = 5 G = 6 H = 7 J = 8 K = 9 My P228 (pictured) is a KH = 97 = 1997 The proof marks can be decoded here: Another way is to check the inside of the plastic grip panels. Goes like this: at the front end of the slide, directly opposite from the front sight, check for proof marks and a date code stamping. Most earlier ones were completely made in W.Germany or Germany. The serial numbers on the P938 all start with “52A0” then all numbers after that are the unique numbers to your. Sig narrowed down the actual serial numbers. 'the initial release of the P938 up until models manufactured to OCT 2012 (per Sig and my research) are the ones that had FTF and FTE issues.
