Could I suggest keeping things a bit quieter about this area? Keep underground gear under cover. I'm told that the local estate isn't too keen on underground access.
The incline is well & truly blocked, filled in by the guys working Grove Rake - because someone was seen going in!
I'd probably suggest a rope on the shaft - it's wide, and the ladder goes right down the middle, supported by a scaffold pole about half way, if it fails you won't climb out of that one.