for some perspective take a look at the nearby millennium minerals, and in particular the bartons underground. the results reported here are very similar and i can imagine that after a small o/p operation that these grades will support a tidy u/g mine. another place to look for comparison is the paulsons mine - yes that little thing that kicked northern star off and propelled them to the company that they are today.
imho the market is missing just how significant these results are, and what they could lead to, having said that the mc seems fair for this stage of the project, so i'm not expecting any great leaps in sp anytime soon - unless there's a t/o offer.