Arthur Jackson has incorrect years affecting copyright

[Mazin]

I was looking at this score: https://imslp.org/wiki/Idle_Dreams_(Gershwin,_George) which is listed PD USA-only. That may or may not be true, because the reason seems to be the lyricist, Arthur Jackson. The page lists him as living from 1911 to 1977, which implies that he was 9 years old when he collaborated with Gershwin to write the lyrics for his musical. This erroneous info probably comes from this other Arthur Jackson: https://en.wikipedia.org/wiki/Peg_Leg_Sam

Unfortunately I couldn't find info on when the Arthur Jackson of Broadway lived. Anyone better than me at searching able to establish when Arthur Jackson died? That could change the copyright status of this score.

[Mazin]

Someone that I reached out to managed to find out that Arthur Jackson died in 1922. If he was the only person keeping that work from being PD globally, then maybe we can change its copyright status.

[Sallen112]

Hmm you got a link to verify the incorrect death date (and birth date)? That does look very suspicious since the file uploaded there was published in 1920, extremely doubt a kid could have written such text. That we would need, not off of a word of mouth.

[Mazin]

Attached is a newspaper article from 1922 about his death. Other records databases might have more info about his life.