Had another quick go at finding this stone today, but with no luck. I asked a couple of people in the village, but they didn't know of the stone, and suggested asking in the Mairie, which was open. The lady there confirmed that there was a menhir somewhere in the community, but that it was mostly buried in a talus (a banked hedgerow) and that she didn't know exactly where to find it.
I guess this stone is not going to be found by luck - and that it will need to be shown by someone who does know.
Something is not right. This message is just to keep things from messing up down the road