I tried to check it out if there are any visual differences between both models that American used to fly in the past. Although we can see that all the B. 720B's they had didn't have the HF
antenna in the tail, there were also some of their B. 707-100B's that didn't have them either, now how could you see the difference? By the registration or maybe looking to their wing roots or maybe the slats that both had. It looks to me that the B. 720B's had more slats than the old generation B. 707-120B's, is that true?