The provisions of these regulations shall not apply to—

(a) Any archaeological or ethnological material or any article of cultural property which is imported into the U.S. for temporary exhibition or display, if such material or article is rendered immune from seizure under judicial process by the U.S. Information Agency, Office of the General Counsel and Congressional Liaison, pursuant to the Act entitled “An Act to render immune from seizure under judicial process certain objects of cultural significance imported into the United States for temporary display or exhibition, and for other purposes”, approved October 19, 1965 (22 U.S.C. 2459); or

(b) Any designated archaeological or ethnological material or any article of cultural property imported into the U.S. if such material or article—

(1) Has been held in the U.S. for a period of not less than 3 consecutive years by a recognized museum or religious or secular monument or similar institution, and was purchased by that institution for value, in good faith, and without notice that such material or article was imported in violation of these regulations, but only if—

(i) The acquisition of such material or article has been reported in a publication of such institution, any regularly published newspaper or periodical with a circulation of at least 50,000, or a periodical or exhibition catalog which is concerned with the type of article or materials sought to be exempted from these regulations,

(ii) Such material or article has been exhibited to the public for a period or periods aggregating at least 1 year during such 3-year period, or

(iii) Such article or material has been cataloged and the catalog material made available upon request to the public for at least 2 years during such 3-year period;

(2) If paragraph (b)(1) of this section does not apply, has been within the U.S. for a period of not less than 10 consecutive years and has been exhibited for not less than 5 years during such period in a recognized museum or religious or secular monument or similar institution in the U.S. open to the public;

(3) If paragraphs (b) (1) and (2) of this section do not apply, has been within the U.S. for a period of not less than 10 consecutive years and the State Party concerned has received or should have received during such period fair notice (through such adequate and accessible publication, or other means, as the Secretary or his designee shall prescribe) of its location within the U.S.; and

(4) If none of the preceding subparagraphs apply, has been within the U.S. for a period of not less than 20 consecutive years and the claimant establishes that it purchased the material or article for value without knowledge or reason to believe that it was imported in violation of law.