1830 Walker Antique map of The Towns of Wilton & Malmesbury, Wiltshire England
(Ref: Tooley; M&B). They had several offices 47 Bernard St Russel Sq (from 1830 - 1836), 3 Burleigh St Strand (from 1837 to 1840), 9 Castle St Holborn (from 1841 to 1847) and 37 Castle St Holborn (from 1848 to 1875).