Most OUT OF BUSINESS casinos still protect their logos.
Example Sands, Dunes, etc still have current copywrite protection. They are renewed every 7 years.
I went to a lot of trouble to get permission to put a Dunes Crest & Seal on one of our chips. After I got permission from MGM lawyers, gaming still denyed it.
The Boulder Club logo is not protected.
The ownership of casino logos can be researched on line.