Your link and the links in the thread referred to in #50 appear to have gone dead. I have yet to see a picture in which my untutored eye can recognize either a plane or plane wreckage.
If that plane was overflying D.C. that morning, it does seem very odd that no pictures have appeared anywhere of the plane in flight.
maybe
this will work? It's a large photo with the upper 70% being firefighters in the smoky distance (70-100 ft) trying to put out the building fire. In the bright green grassy foreground is a man-sized piece of aluminum with what appears to be part of a red curve (circle?) with a thin white border around it. The rest of the piece is unpainted, with lines of regular rivets showing. The curvature of the piece is pretty tight, making me think it might be from the tail, because it's far too small and regular to be from a main part of the fuselage.