Where by or under an Act the use of the Arms of the Territory or a representation thereof, in whatever terms described, is prescribed for a document, form, seal or otherwise as a mark of authority of the Crown, the use for that purpose of a representation of the Arms of the Territory, in the form in which that armorial insignia is or was, at the material time, granted, shall be taken to be and to have always been a sufficient compliance in law with that prescription.