Guys, I'm not sure that cosmos was right. With my humble option the top mike (on his foto) looks more like fake to me. BTW bags for Shure are manufactured in china, otherwise fakes bags have stamped Mexico in common...
Best metode is trust Your ears
Or here are some simple guides, how You can determinate fake/ real SM57 I've found out:
1/ genuie 57 have silver coil, fakes with color as the rest of the mike body
2/ Genuie 57 have resistivity (pins 2-3) aroud 400Ohm max., fakes over 500Ohms
3/ real 57 have aprox. 20 grams more then fakes
4/ real 57 sound 5 times better
Good luck! Michael