Oh dear now I'm feeling really old! I can remember the site after Hitler's bombers had done a good job on it. There was a shop called Salanson's where my Dad got me a Hornby "O" guage Hornby clockwork train set for my fifth birthday. Then everything was demolished and they built Fairfax house and then they pulled it down to replace it with the Galleries.
Yes..they called them Pater Nosters....H&S would go ballistic nowadays. The thrill was to jump on them as late as possible, then stay on them at the top as they clunked across to the other side! Also......PINK Shield stamps and, of course, blue paraffin!
I worked for the Govt for 15 years (Atomic Energy Authority) - the main building was 4 stories high and had a paternoster - if you stayed on it it went over the top or underneath at the bottom We had an apprentice training school at that time and on their induction the instructor went "over the top" and when he came back down the other side he did a hand stand - they all thought the compartment had tipped over - priceless!!