Henderson was a landowner.
He lived at 103 Eaton Place, Bushey Lodge, London, in 1866 and 7a Chandos Street, Cavendish Square in 1877. He owned 1955 acres at Fordell in Fife valued at £5843 per annum in the parish of Dalgety, near Inverkeithing. He may have known JW in the mid 1870s and been invited to a private view as a potential client.
Kelly's London Directory, London, 1866, 1877; www.geo.ed.ac.uk/scotgaz (accessed 2004.04).