Boot- Good to have you here. You obviously know something about the subject.
As to your questions,
1. Efficiency rates- Sounds like you've already gotten the info from RK. I've seen the same numbers around, and I think PQ mentioned them at the SHM.
2. Underground- Again, sounds like you've gotten much of the info already. No permits yet, they're still doing the extra work MSHA added. Then drilling after MSHA's go ahead. Maybe some more work for full mining permitting. As far as the geology, there are a number of good sources. Check out the two in the Link Library- the Piper Laney report and especially the Idaho Geological Survey report. More than you'll ever want. The Sinker is probably de-watered by now, if it needed it. The shafts above that they will eventually connect to will need de-watering before the Sinker connection is made. That should be straightforward.
3. Ore in the Sinker- Again, check out the reports. The Sinker intercepts the major veins, and according to the reports the veins pretty much maintain grade from the surface down to Sinker level. I get the impression from my readings that the Sinker has some offshoots where they were either chasing veins or trying to intercept multiple shafts coming from above. Not sure how the mining will be done. Mention has been made of either trams or a rail system to remove ore.
