Vintage style standard lamp with shade (Cookham Dean SL6)

Heavy black marble base, brass stem, dates back to 1960s at least and has no BS mark . Long flex, height of lamp: about 1.73 m to top of shade. (Cannot work out how to show the whole lamp in the photo If you have the patience to copy and paste the photo, you should be able to see the whole thing.) In fair condition but definitely not as new.