I'm posting this for a friend, who has been attempting to find this book for years. It was one of her favorites in the evening when she was really little, so the time frame is probably late 80's.
This is a book about a mouse, whose name is George (although my friend admitted she could be wrong). It's a children's book, perhaps even a bath book? It's about a mouse's adventures, at one point he is in a castle. The one line she remembers is that the mouse got to find "a morsel of tasty cheese".
If you can find the name of the book, she would be eternally grateful! Extra points if you can find a place where a copy could be purchased :-)