< Lovely to see pics. Should it be a sub site of the Greywethers though? >

Hmmm....see y' point. Will recitify it soon.

The image of "sarsens on Fyfield Down" ( http://www.themodernantiquarian.com/site/256 ) looks especially intriguing. I imagine it's already been examined, but if not, this is just the sort of terrain you'd expect to find cup&ring art. If the Fyfield Downs cup-marking's close by, this is certainly where I'd start to see if there's owt about, checking each & every stone with care.