My wife has a subscription to newspapers.com. After searching, I found 3 articles (in addition to the NY Times).
From the News-Herald, Franklin, PA dated 31 March 1945.
“Mrs. Martha Johnson, negro, named her sons Iwo and Jima.
From the Pantagraph, Bloomington, Indiana dated 1 April 1945.
“Mrs. Martha Johnson, colored, has named her two sons Iwo and Jima”.
And from the Tucson Daily Citizen, Tucson AZ, dated 16 May 1945.
“The names which will be weighting down the youth of our nation after this war will cause teachers untold pronunciation difficulties. Already from Washington, D.C., comes the announcement of the birth of twins, Iwo and Jima Johnson. We may expect to find future lists of school children to look something like this: Chichi Haha Jones, Kurabu Zaki Smith, Formosa Brown and Dusseldorf Jackson. - Truax Radio Post.