Duke's Broither Marries Girl From Grocer's - Tall, red-beard Lord Geoffrey Percy, 30, yesterday revealed ode secret of his register-office marriage three days ago to a girl who runs the general store on a tiny island in the Bristol Channel. The bride is twenty-three-year-old Mary Lea, attractive manageress of the Morisco Tavern and Stores on Lundy Island. The groom is a brother of the Duke of Northumberland, the head of one of England's oldest families.Sitting in the lounge of a Devonshire hotel yesterday Lord Percy told of his secret marriage and of his plans for the future. May 31, 1955.