Just wondering if the signal cabin at Pt Pirie has been demolished recently? I had a look on Google Earth and I can’t see it anywhere. Last time I visited there was a radio station based there, but I’ve seen photos from 2015 that show the place pretty derelict.
Whilst I can't comment on the Cabin, Google Earth can't be relied on as being current. Each image is made up of cloud free "tiles" and could be from any point in time. Usually stacked with most recent on top, but not necessarily.
Hope you find out about the Pirie Cabin.