Re-configured hinge to better transition along trailing edge with hinge rolled portion in line with the elevator trailing edge and tab hinge flipped to make the tab better follow the top skin line (image 3).
Used 1.5v D-cell to test and adjust travel of the trim tab. As configured, capable of 45 deg travel in each direction. With only 1.5v, total travel time from stop to stop is only about 4 seconds. This seems pretty fast for fine trim control.
Decided this would be easy enough to retro-fit to the elevator. Would need to cut a new inspection/access hole in the elevator skin. This would allow installation of the servo, or perhaps mount the servo directly to the inspection cover as an assembly. So, I'll go ahead and rivet up the elevator assembly, T02-02, with no extra provisions.