CB Radio Caper, The / Curse of the Cobra, The (2-in-1 Mystery Novels) by Gary Paulsen

This vintage paperback includes two thrilling mysteries in one! Once you finish the first story, simply flip the book over and start at the beginning of the next! 

Malcolm, better known as Mallard, Westerman helps his father, a police inspector, piece together the clues surrounding a series of baffling kidnappings.