If a document that is or purports to be more than 20 years old is produced from proper custody, it is presumed, unless the contrary is proved, that:
(a) the document is the document that it purports to be; and
(b) if it purports to have been executed or attested by a person--it was duly executed or attested by that person.
Note: Section 182 gives this section a wider application in relation to Commonwealth records and certain Commonwealth documents.