In reply to all:
Alright people, just a quick summary of what's been done today. Trees have been thinned/removed by the Cholera Area buttress, the Empty Quarter and Phantom Wall, so all these areas should get some air circulating and less green mank.
The bottom of the Phantom Wall buttress, underneath Organ Grinder and much of Empty Quarter, and the Cholera Area have been de-brambled (the "bramble-infested slope" by Organ Grinder is no more...).
At least one new route was done, and several others have been done recently in that area of the quarry.
To my inexperienced eye, lots got done, and I'm knackered. Roll on the next one.