Jeff
The "wire" in picture cable1.jpg, in my opinion, is the back end of one side of the "Vee" antenna that stretched from one side of the Vee fixture atop the fuselage to the point where it is attached to the vertical stabilizer. It prolly fastens to the stabilizer with an insulated bolt/nut. Another wire would be attached to the other stabilizer in te same way.
Maybe the plane didn't "tumble" a lot as it slid down the reef slope and came to rest on the plateau? Maybe the plane is relatively intact and the stuff you are seeing is stuff that came outa the door and hatch as the plane slid down the slope.
My guess is that the "rope" is just that, a rope looped around the plane and tied off to something stationary to keep the plane stable on the reef edge. The rope broke and the plane slid over.