Werner Guttentag was a close friend of Werner Jany. They were both from Breslau and later together at the Werkdorp. Martha was friends with both. Unlike Werner Jany, Werner Guttentag was saved. His mother could get him and his father a visa for Bolivia. There he became a famous publisher. (http://lateinamerika-nachrichten.de/?aaartikel=ein-leben-fuer-das-bolivianische-buch)
Addition