This zero-setback partywall block, in Fig.1, can be conjectured typally as follows.
Figure 2 indicates the uses: S, for store; and tenements above.
Figure 1 shows, facing Church Street, a window converted apparently from the original shop door. The photo shows an existing (and original?) door at the fifth bay from the corner. Note, too, that at the sixth bay from the corner there is evidence of a door filled in. There is one bay, a seventh bay, beyond the apparent original door.
There are several possibilities including the following. First, this fifth-bay door on Queen Street could have been a side or service door to one shop on the ground floor or a second shop entry to a store facing Queen Street. Second, this existing door may have accessed a stair to stacked flats on floors two and three. If the flats were accessed by the door at bay five then the door at bay six may have been a second shop facing Queen Street.
There is a third possibility. The original upper story flats were entered from the sixth-bay door on Queen Street. Perhaps in bays six and seven there was a switch-back stair. I will guess that on floors two and three there was a corridor that ran along the south party wall giving access to flats.
The number of chimney stacks may indicate the number of flats or number of rooms per floor. In Figure 2, the two story porch on south side of the building and shared with the next building is yet another clue as to the arrangement of the upper floors.
With so many possibilities, perhaps this is the best typal description.
Zero-setback party wall block with flats above shops