Silver tokens sold as a set in gift shops in the 1970's. I believe there are 7 different hotels. Sahara has two different dates. Generally in the $40-100 range per token. They are not easy to find; thus the uncertainty on value. Not many collectors know these exist.

I'm away from home or would scan the set. I believe the Las Vegas Hilton is one of those you don't list and one of the hardest to find.