I purchased Frederick Forsyth Avenger (Signed 1st Edition) with a black jacket. I just ran across another copy listed as a 2003 1st/1st from St. Martin’s but it has a white jacket with brown (or copper) lettering. Do you know the difference? Or if this book was published with 2 different jackets?

Although it doesn’t happen very often, publishers will print two different book jackets for the same book.  One is not necessarily more valuable (or collectible) than the other.  It is simply a marketing moment to promote the book, and does little more than lend confusion to the collector market.  In addition to the Forsyth example, you will find this on Tom Clancy‘s Clear and Present Danger and well as Lisa Scottoline‘s Vendetta Defense. 

Where is has made a difference is on Terry Brooks‘ novels for Star Wars there are four different jackets showing the characters.  In 1975 Robert Ludlum, writing as Michael Sheppard, released a book called the Road to Gandolfo.  The publisher, Dial Press, could not decide on which of the three jacket designs to use so shipped it with all three.  Finding a collectible edition with all three jackets in tact is quite the find!