William Jeffery is listed as being in business at the following locations;
22 Briton Street and 10 Lockyer Terrace Plymouth,1849
52 Union Street, Plymouth, 1855-62
12 George Street, Plymouth, 1865 in cica 1900 the name was changed to and Son.
Jeffery is the name of at least 8 gunmakers of the era located for the most part in towns and cities in the South/South west of England. There has been much speculation as to their connection with the London based W.J.Jeffrey and other companies trading under the name Jefferies [eg; George Jeffries of Norwich & Lincoln Jeffries of Birmingham] The late Geoffrey Boothroyd researched the complex relationship of William Jackman Jeffery with the other makers trading under the name Jeffery/ Jeffries ,his findings show that there was a connection; the relationships are described in his book,"Sidelocks and Box Locks", pages 61-65.