I flew the Trident 1C for some years from 1968. It had the identical fuselage, and therefore door arrangement, as the 1E. The damaged door section in the photograph does not resemble any of the Trident doors or hatches. It is too small to be a cargo door and too big to be the avionics access hatch. In any case, no hatch or cargo door had an access window, and none of the passenger doors had a window of that elongated shape. I would say that it does not come from a Trident.