Manufacturer
Stanley LondonNotes
Stanley London produces brass replicas and reproductions of antique sextants, compasses, telescopes, and other surveying and nautical instruments. (https://www.stanleylondon.com/)
They stamp their products with "Stanley London" in commemoration of W. F. Stanley & Co. (London), a leading manufacturer of these kinds of instruments throughout the 20th century.
While W. F. Stanley & Co. did use the label "Stanley London" on some of their products, most objects currently in circulation that bear the name are reproductions, not originals.