Not sure if I'm late Pete but it is in Brandywine. It's in the parking lot of the Regency Furniture warehouse (the old Montgomery Wards warehouse).
Turn right off of 301N onto Cedarville Rd and turn left into the gated parking lot after the 7-11 gas station (about 300 feet after the station). At the guard house (there's no guard there) go right then go completely around the warehouse to the right and circle around the back. The Fedex office is hardly labeled but you'll see the window & door. It's small but it's there.