Ann: Assays Confirm Fraser Range Nickel Prospectivity, page-28

Any geo can observe sulfides in RC drill chips with a hand lense...the issue is whilst pyrite and chalcopyrite (Cu) are easily distinguished...pentlandite (Ni) and phyrrotite a bit harder to distingish in drill chips but should be ok for a good geo.

Note 1. Most explorers for Ni/Cu will have pXRF guns on site. Whilst these results are not absolute, they give a good indication of presence/absence of Ni/Cu.
Note 2. If Mawson and Nova are anything to go by, there is a good correlation between % chalcopyrite and % pentlandite, so if cpy is observed, then you've probably got some Ni.
Note 3. You're correct, Sirius initial discovery was with an RC rig.

Regarding the 7cm vein of massive sulfide...it is highly significant. See photo below from Mawson Hole 007. This was followed up by Hole 008 testing an off-hole conductor and that was money.

No guarantees in this game, but often where there is smoke, there is fire.