Can't see any photos of Fleet St on this site however there are many of Charles St.https://imageleicestershire.org.uk/quick-search?q=charles+street+&WINID=1713234077961
Is this the "Cherub" building you meant?http://www.rootschat.com/links/01t4c/http://www.rootschat.com/links/01t4d/And another:https://www.leicestermercury.co.uk/news/leicester-news/gallery/leicester-1960-dip-archive-brings-6936185