Amazon is currently advertising an album entitled "'Happy Days Are Here' - Favourites From The American Songbook" which contains a cut of the song "My Foolish Heart." Martha Mears is listed as the vocalist, but the sample of the song is an instrumental version.
Martha Mears was a singer whom the studios frequently used to dub in the voice of various actresses. She made a rare apperance as herself in the film where she is singing the song. However, she did not sing the complete version in the film. I find no record (as confirmed by your site) that she ever recorded the complete version, except for the amazon offer which your site links to. I would love it if there was such a recording, but it seems there is not. I've contacted the label which released the album, but they have not responded to me. Can you confirm I am correct?