Clifford also did the first ascent of Seb's project on the project wall in Quantum Field, Castle Hill (scoop right of Rocket Pants if you know the area). Seem to remember he gave it v12 or v13.
That problem had been a very long standing project at Castle Hill and a very obvious line. Clifford's ascent started a rush of new, hard problems at the hill and was pretty significant really, pushing grades there beyond v11.