I think G. Gaugusch is referring to Joachim Zeisl, brother of Michael. Those names probably got mixed up at some point, maybe even 150 years ago. I haven't found any other source for Jakob in Mährisch Rothmühl (M. Radiměř). There were quite few Zeisels but not a single Jacob. And Joachim with his family shortly lived there before moving to Svojanov.
Also the theory about Lednice (Eisgrub) origin is wrong, in my opinion. Many Jews at the time were Familiants in different towns (e.g. Hermann Edler von Zeissl in Holešov). From all sources, it is pretty clear, that they come from Lomnice.
7.) Ein Bruder des genannten Michael Zeissl war der in Mähr. Rothmühl bei Zwittau ansässig gewesene Jakob Zeissl. Die Familie Zeissl scheint aus Eisgrub zu stammen; ein Sohn des Michael Z. Moses Zeissl erscheint in den Urkunden als Familant aus Eisgrub. Diese Urkinde aus dem Jahre 1837 befindet sich im Besitz des derzeitigen Bürgermeisters von Zwittau Karl Lick.
