Hey guys. Newbie to the forum here though I’ve lurked around for a while. What does an “M” or “W” (depending on which vantage point it’s viewed from) mean when stamped in a Telecaster neck pocket? One outside “appendage” of the letter is longer than the other. Can someone enlighten me as to who stamps their bodies with this mark? Any help with the other markings would be more than welcome as well. Thanks in advance.