Costing Base Metal Streams in DCF

Hi all,

Hoping for a bit of advice,

When estimating sales revenue for base metals, what methods do you all prefer and what is the accuracy like?
I notice the C1 cost is for payable Zn with credits for Cu ,Ag, Au, Pb etc credited back out of the production costs but the C3 isn't?

With Thalanga being one production facility, I understand the production costs can't be split across each stream of DMT however the revenues are per concentrate DMT (or appear so anyway).

In my model, I've used grades and mass rates + recoveries to estimate DMT output of each stream when Liontown comes on. Is it better to use Zn eq and assume all revenue is Zinc DMT sales and use C3 or is there another way of doing this per stream?

Appreciate any help on this, I know you've all got DCF models up your sleeve ready to crack out sharp answers for me.!

Thanks
BigDog.