A document that purports—
(a) to be a copy of, or a faithful extract from or summary of, a public document; and
(b) to have been—
(i) sealed with the seal of a person who, or of a body that, or
(ii) certified as such a copy, extract or summary by a person who, might reasonably be supposed to have the custody of the public document,
shall be presumed, unless the contrary is proved, to be a copy of the public document, or a faithful extract from a summary of, the public document, respectively.