It shows the 'By Royal Letters Patent' stamp and the two patent numbers relating to this. (A letters patent is a type of legal instrument, in the form of a published written order, issued by a governing power, such as a king, president, head of state, or head of a corporation, that gives a person an exclusive right, privilege, title, or office. A letters patent is not sealed.)

Measuring 9" x 4.5" with two keyholes in the top half and on the reverse are 2 hinge points to allow access to whatever this plate covered (maybe a toilet lock etc)

In lovely condition

Rare collectible on offer