Hello again
Just to start with, it does seem that these HENKE families were probably related (unconfirmed, but they were bracketed together on the passenger manifesto).
You say your gt/grandfather Heinrich was born 1856 ?... though I expect you actually meant "1865" (as is mentioned in other threads) ?
I've looked over your previous threads (going back to 2009) and also viewed a number of "trees" online at Ancestry.
These trees, (and I'm guessing one of them is yours ? ) all carry almost identical information.
They all too, make the assumption that "Harry HANKS" was in fact a man formerly named "Heinrich HENKE" who was born in Germany. But what I cannot see in the various threads and "trees", is "documented" evidence that this is the case ?
And, I think sometime in 2019, mention is made in a thread about a "blog" where you've said (or something similar) ... "we have confirmed our gt. grandfather was actually born in Germany around 1865".
It was not explained though where this information was found ??
On the (WA) death certificate for
Harry HANKS (1943) ... his age is given as 70 years (bc 1873), and his birthplace is shown as "Scotland".
[Included too father's name and occupation and mother's maiden surname. ]And when Harry and Agnes travel to UK in 1929, his age is 64 (bc 1865) ... and again his birthplace is stated as "Scotland". [Noting ... same details appear on passenger list for return journey 1929 to AUS - and also on immigration list when entering Western Australia. ]
But of course the information given in a death certificate can often be unreliable (supplied as it is by a third party).
I can see your previous searching has not revealed any "really useful" background information for "Harry (or Harold) HANKS" ... and because most of his children were born in South Africa, there is difficulty and great expense in obtaining their birth certs - which may (or may not) reveal additional information about Harry.
Considered a much more reliable source (because info is provided by bride and groom themselves), is a marriage record (the registry entry type ($20) - rather than a transcribed certificate).
* Do you actually have a copy of this ? (1893 - VIC ) [Or just snippets from an index ?? ]
* And as Harry married twice, then his second marriage record would probably also be a worthwhile purchase (for comparisons sake anyway.)
I'm happy to pass on to you information I've gathered about the Heinrich HENKE family ... but will await your reply re: the Harry HANKS marriage record(s) before going ahead with this.

[I have to say I'm not convinced at this stage that they are one and the same person.

]
~ Lu
* Edited (some wording) for clarity.