I was doing some work on my 2gen g19 and ran across a post here at GT about mfg dates and serial #s. The post I read was a couple of years old but mentioned a three letter code after the serial # on the barrel. Mine does not have these letters. My serial # is LY ###. Is this something special or am I just missing something? And how do I figure out the date of manufacture? Thanks in advance and God bless.