Lightly grease a cookie sheet or line with parchment paper; set aside. In a large bowl stir together flour, sugar, baking powder, the 1 tablespoon orange peel, salt, and baking soda. Cut in margarine until mixture resembles coarse crumbs. Make a well in center of flour mixture. Stir together buttermilk, egg product, and vanilla; add to flour mixture all at once. Stir with a fork just until moistened. Gently stir in blueberries.
Transfer the dough to a lightly floured surface. Quickly knead dough by folding and pressing gently for 12 to 15 strokes or until dough is nearly smooth. Pat dough into a 7-inch circle on prepared cookie sheet. Cut dough into 10 wedges.
Bake in a 400 degree F oven for 15 to 20 minutes or until golden. Remove from the cookie sheet; let cool on a wire rack while preparing icing.
In a small bowl stir together powdered sugar and the 1/4 teaspoon orange peel. Add enough orange juice or fat-free milk to make of drizzling consistency. Drizzle over warm scones; serve warm. Makes 10 servings.