"The Gambler" was a publication (see scan below) and store operated by the famous / infamous Bill Borland of World-Wide Casino Exchange. The author of the Blue Book and some questionable (i.e. counterfeit) chips.

The Gambler was one of Borland's several side businesses. The catalog sold home-game poker chips, gambling related books, dice clocks, etc.

The P O Box and phone # on the chip was Borland's WWCE number at the time. I don't know why the key return sticker was on the reverse. Perhaps Borland made these as samples and distributed them to motels around town as an idea for replacing the plastic i.d. tags attached to motel keys at the time.

Nice find. If you don't intend to keep it, I may be interested.