I'm in Adelaide and saw your request re Dr. R.H. Thomas.I have taken a while to look things up for you I know, but I have experienced some health problems and my husband and I are in the process of beginning to pack up our belongings and move to a new home (when, and if we find one we like).
Nevertheless, when I was in the library about two weeks ago I had a look through the S.Aus. Directories and found the following.It is not exactly what you asked for, but there is absolutely nobody called Rufus Haydon Thomas in our Directories from 1911 onwards.
What I did find was:-
Thomas R. Haydon Nash.University Lecturer and Medical Practitioner as occupations in the 1911 Directory of South Australia.
I know the "Nash" seems a bit 'out of the blue' but I have copied the information exactly as I have seen it.
Rufus does not appear in the 1913 Directory for South Australia.
I even checked our death records which, at the moment, are in the process of being updated as they only go to 1915 at the present time.It will be months I would imagine before they have finished updating the death records.
I hope this is the person you are looking for.I cannot explain the "Nash" in the Directory Information, but everything else seemed to 'fit in' perfectly, so I am sending the above info. to you.
Hoping it is of some help.
If you ever want info. about anyone who came here int he 1800's feel free to get back to me, preferably, at my email address, and I'd be happy to have a search for you.