Answer June 2021
Click on the images above to see a full-sized image.
This old drinking fountain is on the west side of the old bus station, in Commercial Place off Priestpopple. No doubt it has been out of use for many years.
The other two photos are courtesy of Google Maps Street View. That in the middle is from Priestpopple with the red arrow indicating the position of the fountain. The right-hand photo is also from Street View but dates from 2016; there the fountain has been repurposed as a litter bin, but only holds one empty beer can!
Thanks to Jennifer for identifying the location of this fountain.