Section 21 Works of art, collectors pieces and antiques 97 Works of art, collectors' pieces and antiques 97 04 Postage or revenue stamps, stamp-postmarks, first-day covers, postal stationery (stamped paper), and the like, used or unused, other than those of heading 49.07. Commodity Code Description 97 04 00 Postage or revenue stamp, stamp-postmarks, first-day covers, postal stationery ..,