The thing is, if he went missing in that time frame and if the family cared enough to file a report.... with DB Cooper's likeness being in the media after the highjacking wouldn't it be likely that they would see his likeness in the paper or TV and bring someone's attention to it?
you would think so. if he died perhaps, he had been estranged from his family so long they had either reported him years before or never. i was thinking, given the time frame, he may have changed his appearance for the hijacking..what if he had been wearing long hair and a beard for years..the clip on tie makes me think it was only bought for the caper..not something he wore in real life. and its always possible the police did get a tip from some relative but the tip was lost in the thousands of tips they received. If someone called and said that looks a little like my nephew but i haven't seen him in years and i don't know where he is now.....might be tossed aside by some tip line operator or some desk officer....
If he lived and never was reported missing i would still expect calls identifying him. i think he had radically changed his appearance though...so the sketch might be too far off...if i were assigned this case i would spend a couple of years climbing through every box of evidence on this case...somewhere i bet he was identified but overlooked.