I’ve noticed that the serial number format on wasr 22’s are pretty much the same. 22-XXXX-XX. I’m assuming that the last two digits indicate the year it was made?? I’m curious as to when they were first produced. I have two of them that are only off a couple digits, and have a very low serial number (in the 20’s). They both end in 05, and are engraved very deep. If this does indicate the year manufactured, how far back has anyone seen them go?