It took one hour, but I probably found what I was looking for.. :thinking: or part of it.. :confused:
There are 109 Hall and 80 Clark in the list of Hallamshire Cutlers, but there is only one Hall William, son of John, apprentice to Clarke William (knife maker) and admetted to Freedom in 1813.
Unfortunately there are 12 Clark William and four of them have been apprentice to a knife maker. Clark William son of William seems the only one to be admitted to Freedom, in 1791, after working to Wilkinson John, knife maker.
EDIT: In the Sheffield Directory of 1852 there is a Clarke John, razor manufacturer, 35, and John, inspr. 135 Harvest lane . This could support the fact that the Clarks at one point started manufacturing razors.