armstrong serial/date

[Franklin da Flauta]

I am a professional flutist since 1965, and happen to be a flute repairman since 1982. A client brought an Armstrong flute, serial 102M1862 on the body and foot, and just 62 engraved on the headjoint (that is, headjoint/body/foot do match). I can't find any info about the manufacturing date in the common serial lists. The key design is like old Armstrongs, which is the same as Haynes' "custom" and Gemeinhardt's M2S. Any help?

[JButky]

Most likely somewhere between 1965 and 1970. 102 is probably the model, the serial # begins with the M. The letter prefix covered certain years. This one would be in that range.