If, at the conclusion of proceedings, seized property is to be returned to the person determined to be the owner or agent thereof, the Deputy Administrator shall issue a letter or other document to the person determined to be owner or agent thereof authorizing its return. This letter shall be delivered personally or sent by registered or certified mail, return receipt requested, and shall identify the person determined to be the owner or agent, the seized property, and if appropriate, the bailee of the seized property. It shall also provide that upon presentation of the letter or other document and proper identification, and the signing of a receipt provided by Plant Protection and Quarantine, the seized property is authorized to be released.