We are talking about Omega crystal (hesalite glass) used in (end of 50s) 60s and 70s on the Speedmaster (2915, 2998, 105.003, 105.012, 145.012, 145.022 etc) and the Seamaster 300 (2913, 14755, 165.014, 165.024, 166.024 etc) the 60s and 70s. To distinguish
this is my 4000th post!! so i thought i'd try to do something useful and posting my SM300's is the most useful thing i could come up with. i've been waiting for a strap to arrive which is why i've been quiet over the weekend. it arrived this morning so i'