16 Vintage Hardy Boys books. see pics for titles. The condition ranges from very good to Excellent considering their age.  The publication dates range from 1959 to 1976.   NOTE that there are two copies of volume 2 but they are not identical, at least on the cover.  The font of the number on the spine is different and the top of the cover of one indicates that it is vol. 2. there may be other differences.