I just came back from the Moonlight Ridge/Sth Coast track on 15/2/12. I found that the PB log book is down a crack in the second-highest pile of rocks a couple of metres from the summit. It is about 2m down a narrow wedge between rocks and the metal box is upside-down. There are a few sticks around it where someone has tried to get it out.
If someone was there with 2 walking poles, they may be able use them like chopsticks and lift it up.
Coming down PB to Cavern Camp, there are a lot of big eucalypts down in the bottom half of the descent - especially as the ridge gets very narrow near the bottom. I added some orange tapes and gave the rest of my tape roll to a group I met at the boat crossing who were heading up & back as a side trip.
Matt.