well first, there is a second page of the report which isn't...

well first, there is a second page of the report which isn't available, note the mention of page 3 in the bottom left corner. I hope this page would have details of how they arrived at the NPV value. Second, it's Argonaut's report, they can come to any value they like. 

finally, i did say assume, i never said it was $587m.

heck, i could change the discount rate and the time periods and come to a completely different value, it's all based on someone's perception of the future. No one's right, no one's wrong, but the deposit is big