Fur products imported into the United States shall be labeled so as not to be misbranded within the meaning of section 69b of this title; and all invoices of fur products and furs required under title IV of the Tariff Act of 1930, as amended [19 U.S.C. 1401 et seq.], shall set forth, in addition to the matters therein specified, information conforming with the requirements of section 69c(b) of this title, which information shall be included in the invoices prior to their certification under the Tariff Act of 1930, as amended [19 U.S.C. 1202 et seq.].