Cutting the support blocks and jigging the longerons took longer than anticipated but I am happy that they now perfectly straight. A string line down the outside showed just how bowed up they were. About 1/4" in the middles. The vertical jigs were mitred on the tops to match the slope and then the plumbers straps screwed down to hold the longerons tight. The tail post has been blocked in at the base and sits vertically in the now coped out longeron tip. It will be cut to size after the top longeron has been welded in place.