I would probably just send an email to Nokia and ask directly since this phone is not released yet. I know those usually gets no where, so the trick is to just ask directly like "is the 1700mhz band using IV or IX" and don't even include the reason why you are asking. Usually that's where the low level email support people go "wtf?" and ask their technical lead. If you include too much they would just try to find a reason to deflect the email.

Good luck man.