Thank you for posting your question on History Hub.
Unfortunately a search in the National Archives Catalog did not return results for World War II Passenger Lists, Deceased (PLD). After researching this further a few options were found for you to please consider.
First and foremost I would recommend searching the records of the American Graves Registration Service. The American Graves Registration Service was established by the War Department on September 11, 1943. The purpose of this organization was to locate, remove, identify, and return home the military servicemen who died and were buried overseas in unofficial cemeteries in World War II. A total of 14 series were found in the National Archives Catalog, in various Record Groups, for the American Graves Registration Service during the 1940’s that may prove helpful. Please note that the American Graves Registration Service changed organizations in 1947. The hierarchy of this organization went from the War Department. Office of the Quartermaster General. American Graves Registration Service. 9/11/1943-9/18/1947 to the Department of Defense. Department of the Army. Office of the Quartermaster General. American Graves Registration Service. 9/18/1947-12/21/1951.
For more information about the records above, as well as to inquire about how best to find the Passenger Lists, Deceased (PLD) for the two ships you have listed, please contact the National Archives at College Park - Textual Reference (RDT2) at email@example.com to confer with their experts.
We also located in the National Archives Catalog an item RETURN OF WORLD WAR II DEAD, SAIPAN, MARIANAS ISLANDS in the Records of the Office of the Chief Signal Officer, 1860 - 1985 (Record Group 111). This video is of deceased military personnel being returned onboard the ship USAT Walter W. Schwenk on February 26, 1948.
For more information about the short film above, please contact the National Archives at College Park - Motion Pictures (RDSM) at firstname.lastname@example.org.
A quick Google search discovered the book “Final Disposition of World War II Dead, 1945-51”
by Edward Steere and Thayer M. Boardman. This book has been scanned and is online for free via Google Books and it might help you in your research. Another avenue of approach would be to reach out to the staff at the National World War II Museum for more information on these lists.
We hope this information is helpful and best of luck with your research!
Thank you, Joshua. I have contacted the National Archives at College Park per your suggestion. The book you recommend was a tremendous help in my research. And thank you as well for the link to the video.