We forget the title and author, but my daughter Elizabeth remembers her favorite book from a trip to our library in 1990 or before. I would love to purchase a copy if at all possible! It was a hardback book with pastel illustrations. They story live involved a boy whose mother left him at home while she went shopping. He left on his own adventure with a bear in a top hat who took him to a magical land. They visited a street which had magic shops – a la Diagon Alley (from Harry Potter fame). One store had a basket of unicorns horns for sale. The trip ended when the boy rushed to get home before his mother did. That’s about all we can remember – except the story was so vivid, my daughter spent hours in the backyard reliving it and adding to the wonderful shops in her imagination.