James H. Hallas wrote a whole book on the battle: Killing Ground on Okinawa: The Battle for Sugar Loaf Hill. In the back he lists dozens of Marines as "sources" including my father.
A friend of mine had Eugene Sledge as a professor of biology at Montevallo State University (now the University of Montevallo) during the mid-1970s. He said that Dr. Sledge would occasionally lapse into stories about his war experiences.