My bass Jupiter has the model on the base of the rods supporting the first key. (not a technician, so probably using the wrong terms here, sorry) I suggest checking ALL of your flute to see if it's not hiding somewhere.
Flutes:1975 Gemeinhardt M2 in chrome nickel;1982 Armstrong 80;2006 Yamaha 584
Piccs:1978 Artley piece of crap 15 P;1982 Gemeinhardt 4S;1980s? Armstrong all wood (no model)
Bass:2006 Jupiter di Medici G0199
Treble:2009 Guo New Voice
+ many flute-cousins