This comparison of the center lifting section of the elevator, taken from the 2010 HD video (frame 18 at time 13:37:05), and the Harney drawing of the elevator area, provides the best opportunity, in my opinion, for the positive identification of an aircraft part that is likely quite unique to the Electra.
The four tiny red dots on the photo outline the area of the center lifting section. Although the part is covered partially by what looks like the gear at the end of the message line, enough of the surface of the elevator component can be seen to show the regular pattern of small holes drilled through the part (in its lower right-hand corner) to allow air to escape when the part returned to its stowed position.