Found it on eBay last week. I don't see it listed in the Nevada Casino Promo Tokens book, although it is similar to 180.0. This one does not have the horseshoe & shamrock image, has a reeded edge, and is 39 mm (chip sized) rather than 35 mm. Made of aluminum.

I'm always surprised to find a promo item that is not in the book as it is pretty comprehensive as of the date it was published: 1993.

TGT says no gaming since the 1970's, but seems to me it is still there and I believe it has slots.