In a skillet over medium heat, cook sausage and onion until sausage is no longer pink; drain. Remove from the heat; stir in the apricots, walnuts, garlic, orange zest, 1 teaspoon thyme and salt.
Cut a pocket along one long side of the roast; stuff with sausage mixture. fill pocket in roast with stuffing. Tie roast with string and place on a rack in a shallow roasting pan. Combine the marmalade, broth and lemon and grape juices; pour half over roast. Sprinkle with pepper and remaining thyme.
Bake, uncovered, at 350° for 20 minutes. Baste with remaining marmalade mixture. Bake 20-25 minutes longer or until a thermometer reads 145° for pork. Let stand 5 minutes; remove string before slicing.