Book 1: The Secret of the Old Clock Copyright 1959 (I don't think this is the publication date) Has a red header
Book 3: The Bungalow Mystery 1995 Printing
Book 8: Nancy's Mysterious Letter 1968 Printing Has a black header
Book 34: The Hidden Window Mystery 1956 Copyright (This might be the right date as there is no ISBN) Has a black header
Book 54: The Strange Message in the Parchment Copyright 1977 Has a black header