Unfortunately tommopen - on top of your other assumptions and...

Unfortunately tommopen - on top of your other assumptions and generalisations about the orebody - you're using gold recovery grades in lieu of in-ground grades, which is not actually testament to the in-ground resource anyway.

This is all notwithstanding the fact that the company could, for instance, be clearing overburden to reach the higher grade ore that forms part of their 2g/t+ cutoff grade.

So "with all due respect" you appear to be using the completely wrong metrics to reach an in-ground grade. I might be more impressed if you increased your in-ground estimate by the gold recovery percentage, that might be a good start!