Where a document of a State or Territory of the Commonwealth other than Queensland or of an overseas country is of such a public nature that it would if it were a Queensland document be admissible in evidence in Queensland on its mere production from proper custody, a copy of or extract from the document shall be admissible in evidence if—
(a) it is proved to be an examined copy or extract; or
(b) it purports to be certified as a true copy or extract under the hand of a person described in the certificate as the person to whose custody the original is entrusted.