Just received this today from a fellow collector:

"As to the Zodiac's. They definitely were in the casinos here. I won a complete set and gave then to a fellow collector. Only the Teller House and maybe Colo. Cen Station had their logo on them...I am trying to remember all the casinos that had the Zodiacs. I remember--Red Dolly (a small casino that is still here-took out the machines a long time ago). Also Harrah's was in Central City and they had them briefly. Canyon Casino in blackhawk and maybe one or two others. It is highly probable that a casino or two had them in Cripple Creek as well, but I don't get down there and can't say for sure. Hope this helps."