My calculations were indeed incorrect but what you are suggesting as a potential annual gross sales figure is ludicrous.
In no way will all of the 36,500 tonnes hold ore that has any retrievable value, even at a lower percentage, the report doesn't suggest that but DOES suggest that the total recoverable "higher grade" is 10,500 tonnes, that is a speculative figure which could of course be out in either direction but gives, as you correctly stated circa $4m value during the full lifetime of the operation.
A lot of the 36,500 tonnes will be rock that has to eventually be disposed of, back into the mine to some extent, according to the report.