A few kilometres north from Avebury up towards Swindon at SU094755 is the site of Winterbourne Bassett stone circle. A scattering of stones are shown in a field to the right of the crossroads on the other side of the village of the same name. These were all but invisible from the edge of the road.
This stone stands at the cross roads itself. Whether it was an outlier of the circle, or one of the circle stones I do not know. If you have an engraving in your collection of 16th century literature please scan it and send me a copy - thanks.