Not speaking for the learned members who shall surely weigh in, I have looked into this myself. There does not appear short of the redemption notices and contacting the casino to find these answers! In looking at the official web site of the State of Nevada and plumbing its depths into the various gaminmg regulations and information made available I find no listing or logging of redemption notices or anything else regarding obsolete or retired chips available to the public! You may now wait for the learned folks to come along!