John: If you haven't already you should download Jack Sobon's History American Timber Joinery, A Graphic Guide from the TFG website, or purchase the new book of these articles. Especially part 5 Roof Joinery Excluding Trusses. It has several examples of what you are looking for, such as drawing #9 on page 4. It shows a step lap rafter seat and tail with a peg hole perpendicular to the roof plane. Good luck with your project. Jim

Whatever you do, have fun doing it!