Vintage Beau Monde Chiswick round metal sunglasses

Very rare vintage 1980's (I think) Beau Monde Chiswick silver metal round sunglasses. The silver metal has tarnished so has a great antiqued look; I think if you cleaned them with a silver cloth, you may be able to make them more shiny again if that is what you would like. Lens have a purple tint. In good vintage condition with the all ready mentioned discoloration of the metal and many scratches on the lens. The original case has been lost but they will be sent in another generic case.