Mine took 72 days, via Trust.
And Matt's right. You surely mean you have some separate parts laying around that would require tools to assemble into an operable firearm, and that they won't be assembled until the stamp arrives, right?
ETA: the number to check on the status is 304-616-4500. Have the serial number of your receiver ready when you call. And remember, every time you call, you're taking time from an examiner who could be working on your paperwork, so don't call once a week to check in.