This detail page shows several photos of the book to show what a first edition looks like.  The images are original photos taken of my personal copy of the first edition book. 

Royal Flush: The Fourth Nero Wolfe Omnibus (1965):

• This first edition probably has the most differences of any of the omnibus volumes. 
• The dustjacket has some unique features:
• The front flap has the price ($3.95) at the top and "The Viking Press New York" and "Jacket Design by Bill English" at the bottom in red text. 
• The back flap has four lines of publisher address and information above "Printed in USA" near the bottom.  
• The color of the first edition dustjacket is a different shade of purple than the book club edition. 
• The title and copyright ages are NOT different between the two editions.  The book cover is gray with blue lettering on both the cover and the spine, a lighter shade of gray than the book club edition.
• I have included an animated GIF file that compares many of the relevant points for a clearer understanding.
• The first edition measures 1.65" thick, as opposed to 1.2" for the book club edition
• I also have a video on our YouTube channel you can watch here