Compare to TRR also $2.48* 528/276 = $ 4.74. Lower than the $5.68 compare to RR and that would reflect the lower TRR grades at rounghly half GCU and no silver there to stream to SLW.
SO, I think we can gross up GCU TRR compare price by 50% safely and conclude that GCU might trade in the range of $ 5.68 - $7.11 after our news gets some digestion.
It really makes no sense to be trading at current level from all evidence I can find