Here's a closer view of Grandma's stone showing the detail of the sunflower Gary (the stone mason) carved. The diagonal lines you see are from where the stones were smoothed. Gary drags them behind his tractor on the ground to smooth the stones. It's also what the Kansas pioneers did, except they used a team of horses to drag the stones.
Gary set the stones on a smaller piece of limestone, and set that into a cement base. He then sealed the limestone with a varnish which will protect them from the weather. It also makes the limestone darker than the old stone post.