No person shall be guilty under section 69a of this title if he establishes a guaranty received in good faith signed by and containing the name and address of the person residing in the United States by whom the fur product or fur guaranteed was manufactured or from whom it was received, that said fur product is not misbranded or that said fur product or fur is not falsely advertised or invoiced under the provisions of this subchapter. Such guaranty shall be either (1) a separate guaranty specifically designating the fur product or fur guaranteed, in which case it may be on the invoice or other paper relating to such fur product or fur; or (2) a continuing guaranty filed with the Commission applicable to any fur product or fur handled by a guarantor, in such form as the Commission by rules and regulations may prescribe.