There are quite a few possibly unvisited in the Western area (that are still going):
Lion and Lamb, Little Canfield
Stag, Little Easton
Sun, Saffron Walden
Butchers Arms, North End
Maybe a few in Chelmsford?
I recall we've been maybe just the once, a long time ago to;
Bell, Panfield
Black Lion, High Roding
Vine, Bardfield