I am researching the life of Richard Cadman Etches, a wine merchant and later a British spy, who, at some stage, possibly between 1775 and 1815, lived at 19 Bryanston Street, Portman Square. I want to find out the exact dates and details of other occupants, but I am at a loss as to how I can investigate this aspect further, as I don't believe the Land Registry existed in those days. Can anyone help me, please?