Shipment may not be made until the permit, Form 9 (Firearms), is received from the Director. If exportation is to be made by means other than by parcel post, two copies of the form must be addressed to the District Director of Customs at the port of exportation, and must precede or accompany the shipment in order to permit appropriate inspection prior to lading. If exportation is to be made by parcel post, one copy of the form must be presented to the postmaster at the office receiving the parcel who will execute Part 4 of such form and return the form to the exporter for transmittal to the Director. In the event exportation is not effected, all copies of the form must be immediately returned to the Director for cancellation.