My old text book "Mechanics of Flight" has a picture of a Bristol Freighter tail and declares the lower rudder tab is a spring tab.
The Lockheed Electra (L188) also had a variation of a spring tab on each elevator.
Genghis, when the RNZAF retired the last Bristol Freighter the pilot declared, after the last landing, it was like flying a low rise block of flats from the upstairs toilet however I never knew a block of flats to vibrate as much as the old Bristol Vibrator!