So this auction shows more of the same type of matchbooks being made for other Apollo missions:

https://www.rrauction.com/auctions/lot-detail/337228104988175-apollo-matchbooks-display/

Chat couldn't find any event AT Caesars with those 3 guys.

But the plaque shows the company being based on LV:

So maybe CP sponsored the issuance of the match covers? Or just advertised in a local business?