Plaza hotel-casino is retiring a series of casino chips, and the public has until the end of August to redeem them, according to the downtown Las Vegas property. A total of 13 different table game cheques have been discontinued as of May 2 because the chips either display the Plaza’s former logo or commemorate a past event, a casino spokesperson explained. Guests have until Aug. 30 to redeem the chips at the Plaza cashier cage. According to Plaza’s posted materials , the following chip types will be discontinued: Old-logo series, which includes $500 purple chips with two turquoise inserts; $100 black chips with four green inserts; $25 green chips with two red and two yellow inserts; $5 red chips with three yellow inserts; and $1 blue chips with two grey inserts.…