Does anyone remember a book of pictures each depicting a letter of the alphabet. It came with a booklet with a list of things in each picture beginning with the pictured letter. The task was to find all the things that were hidden in the pictures.
I think I know the book you mean. It was quite small, and had a black cover with a brightly coloured picture on the front. Each page contained a cryptic poem, and the answers to each clue began with the same letter that began each poem. I seem to remember the title was something about a key....
If that's the one you mean, bear with me. I'm thinking.
Maybe I'm thinking of the wrong book. It would be handy if the OP would come back to the thread and tell us more. I've been wracking my brain for a couple of days - possibly for nothing.