Inspired by Bran...There is little hope of anyone knowing the answer, but when I was little I inherited some little oblong books about a family of mice (clothes wearing family), the book was about 10cm wide by 5cm high and the covers were one brown, one blue, one yellow etc and the mice were quite pointy...I suspect they were from the fifties and drawn in typical fifties reading book style just a few words to a page...
And i also came across this website which chooses a book for you based on your inputWhichbook.net