A very interesting series with a history behind it. "Muck," as he was known, Friedrich Muck-Lamberty, was a charismatic young song-and-dance preacher of the "Neue Schar" movement of the Notgeld era. He ultimately impregnated a few too many of his female followers and was forced to leave Kahla/Leuchtenburg in February of 1921. I think the last note shows him being deserted by his followers - what do you think?
Robert Ball Nachf. in Berlin (the Nachf. stands for Nachfolger which means 'successor(s)') is one of the big numismatic mail-order and auction houses of the 1920s, and they are one of just a few Notgeld dealers from the Notgeld era who actually printed their own envelopes with information about the set contained inside. Some are handwritten, others are typed or mimeographed, and some are even specially printed for the particular note or set that's inside. The envelopes have become quite rare, especially in excellent condition, much rarer than many of the original envelopes that accompanied the sets - to the point that trying to find any particular Robert Ball envelope is usually a lost cause. The company assigned their own catalog numbers to the notes, printed in the upper right-hand corner of each envelope.