The mineralisation was from the surface, as discovered by WMC...

The mineralisation was from the surface, as discovered by WMC 1969-71. There was 1 reading of 16.7ms at 1.84% cu from surface.

How much had eroded over time?

Conductor 5 is at about 500ms depth.

RB was at the surface and the presence of the ore was manifested by the gossan. A gossan is how Horseshoe Lights to the west a fair bit (but still Bryah and Narracoota) was discovered in about 1946 but the prospectors and small miners were only after gold and did not recognise the copper potential. It took 40 years for the deeper copper to be found, but that's another story, although still relevant imo.

This is very relevant too for this particular area. It's from F Pirajno's said paper. The intense deformation shown there probably applied here too:



Figure 13.
A two end-member stages model (A) pelitic-mafic Besshi-type lithostratigraphic setting (modified after Galley et al., 2007) showing contemporaneous sedimentation and mafic rocks emplacement with localised development of massive sulphides accompanied by deposition of jaspilitic chemical sediments, followed by (B) intense deformation along a thrust fault zone, in our case the Jenkin fault, in which the mafic rocks and sulphides lenses are almost vertical in present-day situation. Figure is not to scale.