My first idea was to check with Spinetti's store, near downtown.
But I see that's already been suggested on the CCA message board.

In the meantime, I noticed that Sam's Town issued a $5 commemorative chip for "The Killers" in 2016. Obsolete now, but I see that there are 3 of them being offered on eBay for around $50 each (competitive auctions / same seller for all 3).

Here's link for one of them (none are my auctions) --
https://www.ebay.com/itm/405505337042

Good hunting!