I am not of the opinion that working through the findings of other searchers on other forums will be a real help. Online requests and family searches do not always amount to fact, any more than our findings here on R’chat may, and some have found them to be be quite misleading.
We all know of course about the dubiousness of online family trees as a basis for genealogy. Very unsound.(unless certification is viewable)
I am only sorry I am not well equipped with Tasmanian resources as it would be a very worthwhile exercise I think to “start from scratch” with this particular man and his wife.
Perhaps those in the group with such privately held reference material will see the post and come up with something helpful.

Sue