Distributed Proofreaders' page on Geisel has a list of renewal notices for him; on that list, Scrambled Eggs Super! is the only one without a found renewal notice. There's also some theatrical pieces; the trailer for 5000 Fingers Of Dr. T and some WWII material about Private Snafu (PD-Gov) is available on the Internet Archive.
Also "But for two years, 1941-1943, he was the chief editorial cartoonist for the New York newspaper PM (1940-1948), and for that journal he drew over 400 editorial cartoons."[1]; I doubt those were renewed.--Prosfilaes (talk) 14:15, 31 January 2009 (UTC)