FORT WAYNE, Ind. — Services were scheduled to be held here last week for Donald G. Scott, the founder of the Scott's Food Stores chain, who died Sunday of congestive heart failure at the Mayo Clinic in Jacksonville, Fla. He was 91. Scott founded the chain in 1954, after having previously worked at Indianapolis-based Marsh Supermarkets. He sold Scott's to Supervalu, Minneapolis, in 1991, and retired in 1996 after having grown the company to include 18 stores. Kroger Co., Cincinnati, acquired Scott's from Supervalu last year.