When I Googled Mother of Pearl Jerusalem bible, I found many just like this, but with the Star of David in the center. Who knows, maybe I'll find that missing tile among my mother's things.
I don't know the story behind this bible, how it came to her. She had several index cards tucked into it with notes on biblical characters.
When I look at it closely enough, it almost looks like there is a stick figure drawn in pencil in the center, similar to the stick figures on that mysterious piece of paper.