1. In a small microwave-safe bowl, mix currants, brandy, and orange peel. Heat in a microwave oven at full power (100%) just until warm, 15 to 20 seconds.
2. In another bowl, mix 2 cups flour, 6 tablespoons sugar, baking powder, and salt. With a pastry blender, cut in 1/ 2 cup butter until no lumps are larger than 1/ 4 inch. Stir in currant mixture.
3. Add 1/2 cup buttermilk; stir just enough to evenly moisten dough. If dough is crumbly, sprinkle a little more buttermilk over mixture and stir. Pat dough into a ball and knead in bowl just until dough holds together.
4. Set dough on a lightly buttered 12- by 15-inch baking sheet. Flatten into a 1/2-inch-thick round. With a floured knife, cut round in quarters or eighths, leaving wedges in place. Brush dough with about 2 teaspoons buttermilk and sprinkle with about 1/2 teaspoon sugar.
5. Bake scones in a 400° oven until golden brown, 20 to 25 minutes. Transfer to a rack. Serve warm or cool. Break round into wedges.