I have a Theodor Peter Koch who died in Schleswig-Holstein 1824 and married my rellie in Segeberg - she was Anna Wichmann, no dates, but her father was Peter Wichmann 1731 to 1808 and her mother Sophie Hedwig Hoyer 1737 to 1820. I have the Wichman and Hoyer families in my tree. Would also be interested in details of Koch if this is the same man.