So:"If from memory Freida produces 270ktpa copper and 250kozpa...

So:

"If from memory Freida produces 270ktpa copper and 250kozpa gold .....then the NSR would be a very handy amount. Someone may wish to calculate it."
 

OK, I will take the bait:

Cu: 270ktpa at USD$6000/t (recent years av sale price for refined copper) less say 20% for transport and refining => USD$1.3B pa Cu NSReturn

Au: 250mozpa at USD$1200/oz(recent years av sale price for refined copper) less say 20% for transport and refining => USD$0.24B pa Au NSReturn

So your 3%NetSmelterRoyalty at AUD/USD exchange rate of 0.70 produces ===>>> NSR AUD$66m pa to HIG

That's ONLY half of our current market cap. each year - I suppose I could live with that! 

PS In truth I actually would prefer to retain some ownership, but this second-best option may be OK.