Last quarter, SBM recovered 31kOz from Leonora at 4.6g/t Au head...

Last quarter, SBM recovered 31kOz from Leonora at 4.6g/t Au head grade. AISC was AUD$2809. Dreadful.
This was because they are mining the low grade periphery of the Gwalia ore body because the high grade ore at depth is not ready to mine.

The business case to buy SBM Leonora assets in my estimation is something like this:

SLR would follow the existing mine plan at Gwalia and transition into the high grade ore at depth. Head grades are set to increase to circa 8g/t Au. This will pull yearly production up from 130kOz to approx 200kOz and AISC would come down to circa ~$1800 per Oz Au.

That would produce $240 million of annual operational cashflow from Gwalia deeps at a gold price of AUD$3,000 per Oz. I'm guessing these rivers of cash would flow for perhaps 5 years as they mine the high grade ore and more than pay off the acquisition. Then SLR own a mill and optionality to go deeper at Gwalia or mine open pits or both.