PJ2,
Thanks for that info - the control surface seems to be an airfoil, perhaps part of an elevator panel? The HS itself is too big I think for the debris to be part of that. Any information that leads to identifying that piece of debris would be very interesting.
Here is a good view of the underside of the HS/elevator
http://www.samchuiphotos.com/QFnew/DSC_5440.jpg
Edit: the notch in one side of the unknown control surface part shown among the debris could very well be a hinge recess for the elevator panel.
-drl