Hi Peter. We're second cousins - my grandfather was Wm Harold, in between Herb and Arnie. My mother was Vera Kortum, your dad will probably remember her. The doctor in Cooktown was the Qld state medical officer - there is much about him in the archives but he doesn't appear to be related. There were three Wendel brothers from Fehmarn however they are Harold's in-laws.
I have photos of Matthias, Rosina and family, his mother Christina (Kruse) and sister Anna. Also transcripts of Herb's letters home from the Boer War etc. If you contact me by email on firstname.lastname@example.org
then I can send them to you.
regards Gary Hicks