Think it's this route I've done although it wasn't 28m so maybe I've only done half of it. It was the route to the left of Coral Bajilla and isn't in the Rockfax guide and this sounds about right for the grade.
valentinesbabe - Lead O/S - 21/Feb/14 with Kevin Tithe
martin clarke - Lead - 25/Feb/13 with nick andrews, john frost
Hidden - Lead O/S - Feb/06
Hidden - 2006