Answer February 2022
Click on the images above to see a full-sized image
The clue (left-hand photo) is of the S side of Battle Hill in 1954, looking SW, and the demolition site of Nos 22, 20 and possibly No 18 (English/United Presbyterian Church). The archway that is now part of Gibson House can just be seen on the right-hand side. The middle photo is pre-demolition looking towards the same area from about 1905, Battle Hill S side looking SE from the Beaumont Street junction, showing from the right: No 24, No 22, archway, No 20, No 18 English/United Presbyterian Church.
The photo on the right is of the same orientation as the clue, showing the Post Office on the site in 1979.
All of these photo are from the Battle Hill Gallery in the Photo Archive. Click here to see the full gallery.
Did anyone guess the make of car shown in the bottom right corner of the clue?
I think it is one of the Standard Vanguard Phase III models, possibly the Standard Ensign. WIkipedia has an article about the Standard Vanguards (click here for the article), which includes a photo of the rear of the Ensign, reproduced below.