The kind of information you received from your friend is priceless, you are fortunate to have such a friend. I would like to have the chance, ability and time to roam the property of SFMI and check out the sinker tunnel. I think the sinker tunnel was originally driven to drain the water from other mines on the mountain, now it looks as if mining the gold and silver ore from the sinker may fund the whole operation. The mill should be able to extract 75% or more of the pm without the leaching, then when all the pm that can be recovered from the milling, the balance can be stockpiled for future leaching.
We have here a resource that is in our country, priceless.
Red