The 8th piece in the Husumer Orgelbuch is a Präludium and Chaconne in D Major. The author may be Christoph Wolfgang Druckenmüller, but the critical notes in my edition seem to indicate that the authorship cannot be determined with complete certainty.
A Präludium in ABA form is followed by a Chaconne with a 6 bar theme , 13 variations, and closing coda.