The gentleman pictured below with Elvis is Jerry Seibel. He was casino manager at the Frontier in 1971 when the picture was taken he was close to 60. He had a long history working in LV casinos and a 2nd career as an amateur & professional boxer right along with it. Sugar Ray Robinson had an amateur record of 118 & 1 before he turned professional. Sugar Ray's one loss was to Jerry.

Jerry's 1st job in LV was the Flamingo in 1946. I don't remember how long he worked there but he rose to asst casino manager.
He was a friend for many years.
Before he passed on he called me and ask me to come over. He gave me a large slot cup full of chips.
I won't describe all of the valuable chips that was in the cup, but there were 12 of the chips in your scan, different tables and colors. He said he had kept them as souvineers of his first job in LV.
Rest in peace friend.