Ian -
This refers to the southern section of Duke Street, now usually called Market Hill. Many of the properties here were demolished in the 1890's and more in the 1930's. Photofinish dates from the early 19th century, the properties beyond towards Victoria Street were demolished to widen Lord Street. The south side was rebuilt (further south then originally) in the 1890's.
The Valuation Plan of 1842 lists the property owners as:
East Side from the Market:
Robert Moore (corner Chapel Row)
Philp Moore
John Stephen
James Hodgeson (corner Duke Lane)
West Side from James's Street:
W & R Duff (corner)
William Duff
John Stephen (corner with Lord Street)
The poetic reminiscences of William Gell of 1918 stretch back well into the 19th century. He recalled the following traders/occupiers:
West Side:
Henry Fargher (Butcher)
East side
Haltons (Drug Store)
Henry Davis, butcher (corner Duke Lane)
Thomas Fleming (Butcher)
Unspecified side:
Matthew Wilson's Cookshop
James Kissack (Grocer)
Robert Clucas (Draper)
Mylchreest later Young's pharmacy (business said to be 137 years old in 1918)

Happy hunting