It's been a few weeks since OBON 2015 shared that they had successfully located the family of Mr. Ueda. Yesterday they contacted me with more details surrounding his family. Rather than paraphrase, I've copied and pasted what they shared below:
Sukio's family is undecided. The wife, who is 82 years old, has been in and out of the hospital. She used to live by herself, but she moved into her daughter's house since her health declined.
Sukio's wife didn't know anything about Sukio's military experiences. They got married after Sukio came back from the war, and Sukio never mention anything about his service.
Sukio had one daughter. Sukio died when his daughter was about 10 years old. So they had no idea about Sukio's military experience.