Don;

I think I can add some data related to your Mint card.

I have in my collection a card that looks very much the same
except it is black on silver and issued for Del Webb's Nevada
Club in Laughlin. Vintage is 1985 or 86 I think.

The card identified you as a slot club member and the machines
as you played spit out 2 x 2 tickets that you collected to indicate
your amount of play, you then took your card to the club booth with
your pile of tickets and they credited play to your club account.
The card was not inserted in the slot machine.

Jim