The UNLV Library has files & info on lots of casinos, gaming people, etc.

Here's info on their Clifford Jones file, including photographs, etc. Mentions that it has "a number of photographs [that] document the family's time in the Dutch West Indies in the 1920s ..."

Unfortunately, it looks like you have to go to the library in person to look at it.

You might check further with the Center for Gaming Research at UNLV, because they do have some stuff (pictures included) on line. I didn't do a thorough search.