I have never seen any other similar memorial in London but perhaps I've never looked.
I think they "just fade into the background - there are many memorials around London to the vicitms of the air raids.
For example Bethnal Green underground
There are memorial from the First War as well
This is a photo of the
Upper North Street School Memorial - this one is poignant to me as my grandmother, although not a pupil at this school, remembered seeing the survivors being pulled from the debris. She said that they were covered in dust and looked yellow. My grandmother would have been 7 at the time.