Wow, 18thc early 19th? I had no clue it might be that old! I had only seen the slanted gout stools before. This does look like it was intended for a single foot. I took a good look at it in the light this morning, looking for saw marks. There are no signs of a circular saw and while the legs look pretty uniform, I can see a slight variation in the curves of the spans between the legs. I can't see any signs of hand tool marks, probably because of the layers of paint. There is a funny mark on the spans between the legs, but this appear to be on some kind of extremely thin wallpaper stuff or in the paint. In just the right light I do see vertical straight saw marks, that go against the grain of the wood. This is cool, I didn't expect this.
Here's a pic of the wallpapery stuff and the marks in it, It is at a crooked angle to the piece and is over the top of the straight saw marks in the wood. Is this some sort of papery liner that would have been on a roll pulled through some kind of machine? It is only on the underside, its so thin it's almost like paint. I've never seen this stuff before.
I will try to get a pic of the straight saw marks.