HI! I was wondering if you had any more info pertaining your father/half sister situation.The long short, my mother was born in seoul in 1948; or so that is what her adoption papers say. Im sure it was common around those years for many half white children to be born, but it's always worth a shot to find out more. Anyhow, she is 64 now. From what she remembers her father was in the US military. He would come by every so often to visit. She remembers his uniform and that he had orange/red hair. We always joke and say maybe we are part irish. My little sister was even born with fire red hair and we are 75% Asian! My mother had a little brother maybe about 2/3 years younger which was from a different man so he (my uncle) is 100% korean/asian. My mother was also adopted when she was about 11ish. She was sold on the black market and was not allowed to bring any piece of her childhood/life in korea with her. Her birth name was Choi, Kyung Soon but maybe thinks her last name was Kim because she also remembers hearing Kim Kyung Soon.Unfortunately she has no memory of her fathers name or history. I thought to reply to your post for everything I may know thinking that maybe your father told you something that rings a bell after my response. If not, good luck with your search and thank you for your time!