No oily screws, but there are some waxed up 18" lags that go in from the top of the rafters down through the plate into the posts. there are 2"x4" tennons on top of the post with a step-lapped rafter seat. also lags at the top of the rafters into the ridge. Your correct about the brace, one lag at the bottom mortise but they fit very tight into the shoulder cut and tennon at the top that no lags were needed.
