Last month I got the book Black Sea Colony of Katharinental by Thomas J. Hoffman. It has 65 pages and contains the names of the immigrants in Katharinental, their children and some grandchildren. This list is very detailed but not necessarily complete. E.g. my ancestor Georg Janzer (1792) is mentioned and also his son Franz (1835), but not Franz’s wife and children. The Hoerner family is missing completely.
t is certainly a very good basis for your own research.
Unfortunately, this book contains almost nothing about the history of Katharinental.
Names mentioned in the book:
Bernhard, Baumann, Binkmann, Boehm, Bullinger (very detailed), Butsch, Daub, Dietz, Deibele, Dilger, Doll, Fütterer, Flink, Haaf, Hammel, Heidt, Hauser, Janzer (Yantzer), Jochim, Kastner, Keller, Klein , Köhler, Kunz (very detailed), Lorenz, Martin, Meier, Mildenberger, Mischel, Pfau, Ressler, Rung, Schilling, Steiner, Stroh, Veitenheimer, Weiler.

You can by the book here:
https://grhc-northdakotastate-ndus.nbsstore.net/black-sea-colony-katharinental-russia