I am specifically referring to the SURAD, that was installed there and was operating in Aug '81. The PPI (Plan position indicator) that the controller had access to, was centred on Williamtown airport, and the outer edge of the PPI was 48nm. The MTI (moving target indicator, for those of you playing along at home, like a filter for clutter) was set at 44nm. There were range rings at every 10nm on the PPI, and a compass rose set around the outside edge. There were permanently displayed 'echoes' between 44 and 48nm that were the Barrington Tops.
There were other radars at Williamtown (and still are) but the only one being used for ATC duties, or even manned, on that night was the one I just described above. Would you like me to send a picture?
As for the last part of your post, you'll have to PM me.