Charles Haberl has posted a couple of things on his blog Philogastry, about a particularly intriguing Mandaean text, known as Haran Gawaita or “The Great Revelation”:
Legends and Lore in the Great Revelation
Legends and Lore in the Great Revelation, continued
I also came across an article by E. S. Drower, “Mandaean Writings,” that has been added to the Internet Archive, and a PhD thesis by Max Aplin completed at the University of Edinburgh, “Was Jesus ever a disciple of John the Baptist? A historical study.”