Preheat oven to 350 F. Fill pasta shells with salmon mixture. All the filling should fit into 18 shells as they are nicely ‘overstuffed’. In a small bowl, mix together remaining dill sauce, reserved salmon juice & mushroom soup. Spread some sauce over bottom of a 9 x 13-inch baking pan. Lay filled shells single file in pan. Pour remaining sauce over all & top with grated cheddar cheese.