I'd be interested in hearing from anyone with any kind of Australian 'Danckert' connections, as apparently there is only one line in the whole country!
The furthest back I have traced is 'Henry Danckert' (my g-g-g grandfather) who had at least one son, John Danckert (b. approx. 1871 somewhere in Australia, probably VIC or NSW). I've also found a 'Mary Danckert' born in NSW in 1867 to 'Henry F. Danckert' and 'Sarah A.' Perhaps Henry's wife was a Sarah? I'd love to find out.
I have found a shipping record for a 'Henry Danckert' who arrived in Australia aged 22 in January 1859. I suppose this could be him.