[aerohead]

Since the Bug shares a lot of architecture, and almost identical Cd with Carl Breer's 1934-1/2 Chrysler DeSoto Airflow aerodynamic test mule, it might pay to re-visit what he did to get to Cd 0.244.
Without a plan-view of your tail, I have no way of advising, but it looks pretty aggressive, and I've seen no evidence that the ( Richard ) von Mises' reflex-camber would benefit the drag.
You're the captain, so you decide, but you're looking at maybe 500-man-hours of fabrication plus materials, and it would be a real shame to have to redo it.