Any document purporting to be signed either by one or more of the Commissioners, or by their order, or by any other person with their authority, shall, until the contrary is proved, be deemed to have been so signed and to be made and issued by the Commissioners, and may be proved by the production of a copy thereof purporting to be so signed.

That Act shall, as applied by subsection (2) above, have effect as if the persons mentioned in paragraphs (a) to (c) of that subsection were included in the first column of the Schedule to that Act, and any of the Commissioners or any secretary or assistant secretary to the Commissioners were specified in the second column of that Schedule in connection with those persons.

A photograph of any document delivered to the Commissioners for any customs or excise purpose and certified by them to be such a photograph shall be admissible in any proceedings, whether civil or criminal, to the same extent as the document itself.