John? James? Jerry?
John I assume https://www.ukclimbing.com/logbook/crags/drws_y_gwynt-203/tombstone_wall-631576
https://xcmag.com/magazine-articles/a-little-closer-to-the-soul-of-john-silvester/
https://pertex.com/stories/making-adra
Nice, good research. I've had a flick through some of the old llanberis guides and added some of his FAs.