Preheat oven to 425°F(210°C). Combine dry ingredients and grated orange peel in food processor fitted with a metal blade. Whirl until blended, about 20 seconds. Cut butter into cubes and add. Whirl with on and off motion until mixture resembles course meal; pour into mixing bowl. Stir in whisked eggs and sour cream jusg until ingredients are moistened. Turn dough onto lightly floured surface and knead gently for about 2 minutes. Roll out dough to ¾" (2 cm) thickness. Cut out scones using a 3" (7.5 cm) cookie cutter. Place on a greased baking sheet. Brush tops with milk and bake for 15 to 17 minutes or until tops are golden and crusty. Remove to a rack to cool. Makes 8 scones.