I did find their web site (http://www.watheroo.com/) and sent them an email. I probably won't hear back until Monday. There's an interesting hand-drawn map there which shows the site of the "old magnetic observatory." Another site shows the population within a 7km radius as approximately 89. A bustling metropolis indeed.
Thanks for trying, everybody. I'll contact the Geoscience Australia folks and see what they are interested in and/or can help me with. I'm also going to contact the Carnegie Institution, who were his employers at the time.