dave, There is a listing in Boothroyd's Directory for Adams & Co.
at 9 Finsbury Place from 1870-1880 . Also a listing for
Adams Patent Small Arms Company Ltd. from 1864-1892, with their
factory at 9 Finsbury Place and retail outlet at 391 Strand,London
Looks like Robert Adams 1809-1870 started the Co. and was associated with George and John Deane, also had two brothers, Henry and John who ran associated companies and shared premises.
Pretty complicated.I have an interesting 16 ga. hammerless,triggerplate,forward underlever cocking gun by Adams and Co.and have seen various others that were very nice quality guns.
Enjoy, Terry