If you really want stunt speed just time the stunt pattern from launch to passing the start point. In between do all the maneuvers, one per lap, no scoring, the timer, or maybe an assistant, just verifies that each maneuver had all the needed points as in the pattern, but don't give any points for the maneuvers.
The clock starts when the plane is released. Any time after it passes the takeoff point the flyer does a reverse wingover, even something as simple as a wide overhead eight outside loop first, comes down, fly past the start, do three loops, pull out upside down, do six level laps inverted, after passing the start point do 3 outside loops, and keep on going.
Something like that will bring back the spirit of 1949- fast planes flying a fast pattern.