Ship’s or sea stores, supplies, and equipment of a vessel wrecked either in the waters of the United States or outside such waters, on being recovered and brought into a United States port, and like articles landed from a vessel dismantled in a United States port shall be subject to the same Customs treatment as would apply if the articles were landed from a vessel arriving in the ordinary course of trade. Parts of the hull and fittings recovered from a vessel which arrived in the United States in the course of navigation and was wrecked in the waters of the United States or was dismantled in this country are free of duties and import taxes, but if such articles are recovered from vessels outside the waters of the United States and brought into a United States port, they shall be treated as imported merchandise.