In reply to jo mt:
It's a great book if you can get hold of a copy! Many great days out provided. It's long out of print though and folks guard their copies closely. You could always join the Avon Mountaineering Club who have a copy for members to borrow.
That said, these days a lot of the information in the book can be peiced together from other sources.
The sport climbing is in the Bristol Sport book and the bouldering in Esoteric Bouldering. Many of the shorter trad lines from Frome Valley Sandstone actually do appear in Esoteric Bouldering as highballs. So what's left is the taller trad.
The Winterbourne Down section is available on the GWR website:
https://greatwesternrock.co.uk/winterbourne-down-extract-download/
There's an excellent documentary/film on the area which shows most of the best lines:
https://youtu.be/6-hMFLSJHbY?si=6V-rE64GvPmKCyrG
Martin Crocker also describes lines on his website, mostly odds and ends and corrections, with no topos:
https://www.martincrockerclimbing.com/s/Frome-Valley-more-routes-k9jm.pdf
I think the only area really unavailable anywhere else is the bit on Bromley Heath, which has questionable access regardless.
Somehow the mystique suits the area I think.
Post edited at 07:30