Into a large bowl sift together 2 1/4 cups of the all-purpose flour, the baking soda, the baking powder, and the salt and stir in the whole-wheat flour and 1 cup of the oats. Add the buttermilk and the egg and stir the mixture until it forms a dough. Turn the dough out onto a floured surface and knead it, kneading in as much of the remaining 1/4 cup all-purpose flour as necessary, until it forms a manageable but sticky dough. Halve the dough, form the halves into round loaves, and put them on a greased baking sheet. Sprinkle the loaves lightly with the additional oats, dust them with flour, and bake them in the middle of a preheated 350°F. oven for 30 to 35 minutes, or until they are browned lightly. Let the loaves cool on a rack.