As one of the original diggers of the new connection between Carlswark and Merlin Mine, we were worried about the scree slumping into the connection crawl/grovel/slither.
I had heard a couple of years ago, before I left the UK, that the connection was blocked, I toddled along to check for myself. It was still open.
As you drop Eyam Dale shaft, before you hit the bottom, go left into a small aven instead of right into main system.
Theres a gap at floor level for a slither into another small chamber with a scree cone in the middle. On opposite side there is a wide hole to John Becks original concrete plug.
As you get to the concrete there is a gap on the left for the slither through to Merlins.
Thats how it was, thats a couple of years ago......