This is a set of 6 vintage, red hardcover books from the Happy Hollisters Children's Mystery series, published by Doubleday Books, by Jerry West. They all have a slight musty smell, and there is no writing inside except where noted below.

1) The Happy Hollisters, 1953; there is some personalization on the inside of the front and back covers, some shelf wear on the spine, see photos;

2) The Happy Hollisters at Lizard Cove, 1957; there are some light brown stains on the inside of the front and back covers, see photos;

3) The Happy Hollisters and the Mystery of the Little Mermaid, 1960; there are some light brown stains on the inside of the front and back covers;

4) The Happy Hollisters and the Cowboy Mystery, 1961;

5) The Happy Hollisters and the Whistle-Pig Mystery, 1964;

6) The Happy Hollisters and the Ghost Horse Mystery, 1965.

Please contact me if you have any questions or would like additional photos or information. Thank you for looking.