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.
1975 Gemeinhardt M2 in chrome nickel
1982 Armstrong 80
2006 Yamaha 584
1978 Artley piece of crap 15 P
1982 Gemeinhardt 4S
1980s (?) Armstrong all wood (no model)
2006 Jupiter di Medici G0199
Plus many many flute-cousins....