For the purposes of section 9401 (relating to Federal findings of death or other status as evidence) and section 9402 (relating to Federal reports of persons missing in action or interned as evidence), any finding, report, or record, or duly certified copy thereof purporting to have been signed by such an officer, or employee of the United States, as is described in sections 9401 and 9402, shall prima facie be deemed to have been signed and issued by such an officer, or employee, pursuant to law, and the person signing same shall prima facie be deemed to have acted within the scope of his authority. If a copy purports to have been certified by a person authorized by law to certify the same, such certified copy shall be prima facie evidence of his authority so to certify.