Couple of more (possible) Christianised sites in Essex - the church of St Mary the Virgin at Great Canfield (with the interesting fylfot/pagan reliefs in its porch, and a single large stone in its south wall). Also a similar large stone in the north wall of the Church of St Mary the Virgin at Little Baddow (notice the puddingstones and Roman tiles/bricks in the wall here). See http://www.themodernantiquarian.com/img_fullsize/75962.jpg and http://www.themodernantiquarian.com/img_fullsize/75961.jpg