This link [1] is from the Library of Congress, saying that it was copyrighted although the date may be wrong. Just search the album up. It says 1951, but it's really 1947. I emailed them to fix the problem so if they have by the time you're reading this message, disregard it.
This link: [2] is a search of the Copyright Office's 1978-present records. You may find future incarnations of the album here, but not the 1947 version which is the cover file. Therefore, it's copyright was not renewed after January 1, 1978.