MGM Grand has completed its acquisition of the Desert Inn and the Sands hotel-casinos in Las Vegas . . . Raymond James & Associates Inc., a St. Petersburg, Fla., brokerage, said it holds a 5.5% stake in Morgan, Olmstead, Kennedy & Gardner Capital Corp.'s common shares outstanding . . . Los Angeles-based Farmers Group said 1987 earnings should range from $3.55 to $3.60 a share . . . Oakland-based Safeway Stores Inc. announced an agreement with Acadia Partners of New York under which a new company controlled by Acadia will acquire Safeway's Little Rock, Ark., division. Acadia is an investment group whose partners include the Robert M. Bass Group Inc., American Express Cos. and Equitable Life Assurance Society.