If you're interested in Nevada gaming research & history, you may want to check out the UNLV Gaming Studies Collection, located on the UNLV campus. I've been there twice, though just for a few hours.

They have a website, which is pretty interesting to explore at:
http://library.nevada.edu/speccol/grc/index.html

Also, on that site, check out the Xanadu Project, an unbuilt casino of the 70's, including some period pics of casinos at:
http://www.unlv.edu/centers/gaming/Xanadu/others.html