Full 8 figure grid ref (from English Heritage scheduling) = SS13084458
Thanks to the detailed English Heritage directions I definitely found this stone. I would add though that this is not in a 'wall' as you and I might think of as a field wall. It should really be described as the last remains of an old field wall, i.e. you can clearly see a few stones that are in some sort of line, but that's all. The 'standing stone' does stand out because it is very wide (1.4m - actually slightly wider than it is tall) and like most of the Lundy stones it is not earthfast (i.e. it is set on the ground rather than in the ground and has stones packed around its base to keep it upright).