There were other Assay Offices that closed before the end of the nineteenth century, such as
Newcastle and York. The following books have useful information on these and other offices.
Frederick Bradbury, Bradbury's Book of Hallmarks (Sheffield: The Sheffield Assay Office, 1927 - 2004)
Ian Pickford (ed.), Jackson's Silver and Gold marks of England, Scotland and Ireland
(Woodbridge: The Antique Collector's Club, 1989)
Phillip Priestley and Maurice H. Ridgway, The Compendium of Chester Gold and Silver Marks 1570 to 1963
(Woodridge: The Antique Collector's Club, 2004)