If I recall correctly, the Fairchild FH-227B had a wedge-shaped bit riveted to the trailing edge of the elevator for, as I was told at the Fairchild factory many years ago, to enhance elevator feel and to prevent the onset of flutter, if the larger propellors were fitted...those being required for increased MTOW.
This aircraft had a higher Vmo than the other F.27's, so additional elevator flutter protection was felt necessary.
Hope this helps.