conso,
ref 1) both HS missing
The left HS is shown in posts 730 and 762.
oldoberon, ref your interest in the aft frame at the HS,
Here is the frame during assembly. The large diameter tubes go to the pivot points of the HS center box, which are located on two fittings that span the gap between the upper and lower frames.
Those fittings and tubes are removed during the HS installation, shown in this screenshot at 5:30 in this video
https://www.youtube.com/watch?v=03Zgs8WCArw This video also shows installation of the aft cone at 5:49, the VS at 6:15, the APU at 7:09 and one of the flight recorders at 7:32
In the video you posted,
https://www.youtube.com/watch?v=6OQigxFYIUg, the fittings and pivot point, but not the tubes, are shown installed at 2:05.
And from the photo of the wreckage, two-thirds of that frame, other structure and the HS are gone.
