I can see a potential where the product produced is in a lag...

I can see a potential where the product produced is in a lag situation for the June Qtr, and was in an advanced situation for the March Qtr.

as we know, the March Qtr production benefited from a larger than usual HMC stockpile coming from the December Qtr.Due to the downtime of the DMU in the March Qtr it's likely that KMS used up most of the HMC produced in the March Qtr and ended with low HMC stockpiles. This would mean that the June Qtr production didn't benefit from a HMC stockpile from March but conversely would have ended up with a HMC stockpile at the end of June which wasn't shown as final product.

i imagine that this scenario would play havoc with trying to work out grade like you've been attempting?

So on the basis foreshadowed above a steady state production level for Sep and Dec qtrs that generates revenue of circa $70mil under current OS, cost and pricing conditions looks pretty realistic to me.