It's probably too soon to speculate but I wonder what caused the crew to reject. If they heard a loud sound, could have been the fuselage breaking apart or something else? From the pictures, a very peliminary observation is that the aircraft broke along the splice lines. If it was structural, how many more of these older classics are there running around with questionable conditions? If the FAA and the NTSB look into this, a lot of carriers could get hurt. Part 26 was created just for this kind of situation, very old aircraft running around with potentially dangerous problems. I am afraid this could start the death knell for the grand old lady.