After missing these stones on my last visit to the church (it was raining!) It was time for a re-visit. As you walk up the path to the church the stones are hiden in the hedge to your right. They are in a line and do look like head stones except the two largest which a squarish blocks covered in ivy. Easy to miss unless you are specifically looking for them. There are many large stones embedded in the foundations of the church itself. Most easily seen around the back of the church. I like visiting old country churches. They are very peaceful and interesting places to visit - this is no exception.
I noticed the large sarsens under the church - I had forgotten they were here, but they're big enough to draw the eye. I had to feel they were useful foundations (the church is a real mismatch of materials and styles - interesting but locked). But at the end of the day, where did they come from? If they were from a circle, incorporating them was making a statement one way or the other. Maybe they weren't and were just lying around - it's not so far to the greywethers. But it's all very interesting.
I assumed from afar that the ones in the boundary (mentioned below) were gravestones and did not look at them properly.
The church at Ogbourne St Andrew has large sarsens in the boundary hedge, one large one and a row of smaller ones. These are reminicent of the Churchill Village stones. The Church itself is built on a foundation of large sarsen stones. I would like to think that there was once a stone circle here. The church is positioned on a raised circular platform. After reading Rhiannon's posts, I think this is possible.