Hi Anne,
I have found entries for various Durkin butchers in a combination of Gore's & Kelly's Directories stretching from 1896 to 1970 - have photographed all the entries and can post them here if you like.
The directories are split into 3 sections - all listed alphabetically: streets, names & trades. So you can look up any one of 3 very easily.
I looked up 78 Soho Street in the 1916 Gore's Directory:
Soho St
78, Durkin, Patrick A., pork butcher.
It appears that he was in business with his brothers also (from other entries). Later on, ca, 1955 onwards, a James Durkin & brothers are carrying on. Whether or not they are Partick's sons remains to be confirmed, but I suspect they are.
I should also add, that there are numerous entries for O'Malley, Stanton & Staunton butchers. A HUGE extended family business!
OK, enough for the moment.
:-)
John