He was originally screen tested as a member of Frank Sinatra's casino robbing team. Unfortunately, the studio saw him as "too young looking" and they didn't believe the audience would view him as a guy in his forties. He was 34 at the time.

For a bit of Rat Pack trivia check out the second picture (the one with Peter Lawford). The suit Dean is wearing is actually Dean Martin's. It's the same suit that Dean Martin wore in the famous Rat Pack photo in front of the Sands casino sign.

The reason Dean Davis had it on was that during filming of one of the scenes a waitress "accidentally" spilled a tray of drinks on Dean after he pinched her butt. Dean Martin was the same size as Dean so he had him run to his trailer and pick out a suit. This suit was also the inspiration for the book entitled, To the Girl Who Took My Pants which featured letters and notes by Dean Davis. The book was written by Thomas Petrick and sadly has been out of print for a few years.

Click on the Ocean's 11 paperback picture to get the full scoop on who the adaptation (supposedly).