(a) Port Directors of U.S. Customs and Border Protection shall permit the export without a license of:
(2) Parts, components, accessories, or attachments for USML Category I firearms, except barrels, cylinders, receivers (frames), complete breech mechanisms, or fully automatic firearms and parts and components for such firearms, when:
(i) The total value does not exceed $500 wholesale in any transaction;
(ii) The export is to Canada for end-use in Canada or return to the United States, or temporary import into the United States of Canadian-origin items and return to Canada for a Canadian citizen; and
(iii) The exporter makes an electronic declaration to U.S. Customs and Border Protection pursuant to §123.22(a), and the exporter is eligible to export under this exemption pursuant to §120.1(c) of this subchapter, unless the electronic submission of such declaration is unavailable, in which case U.S. Customs and Border Protection will issue instructions