Craidg, the patent referred to here is the James Purdey & Son patent that was licensed to many gun makers at the time. Dickson built quite a few hammer guns likes this, each stamped with a use number issued by Purdey.
Daryl, the Dickson Patents I have are as follows:
Dickson No.294 of 1880 for bar cocking slide
Dickson and Murray No.873 of 1882 for two and three barrelled guns
Dickson patents No.9399 and No.10621 of 1887 for ejector and improvements.
Dickson and Morrison No.21681 of 1910 for single trigger
Which don't tally with your dates, know something I don't?
