I am also a decendent of the Blohm family from Stade, Hamburg. I have a Johan mathias Blohm born January 1 1729 who married a Johanna Regina Tandt.Furthermore, the mail lineage goes on to Otto Friedrich Blohm born Sept 2, 1778 wh married a Caroline Plate. Next came Karl Otto Blohm born June 1, 1813 and married Caecilie Amalie Wilhelmine von Sode
The next one immigrated to Brazil: Otto Friedrich Viktor Amadeus Blohm born Feb, 11 1850 and married a Wanda Schrader. Following was my grandfather Franz wilhelm Blohm who married Clara Lise from Berlin (sorry no dates here) After thatt came my father Walter Volkmar Blohm followed by myself Ingrid Blohm born 1960.
If any of these ring a bell in your ancestry chart let me know.