Update from this morning! See attached video, and photo in next post.
It's possible this is a different bird. But same size, same spot, same time, there aren't that many birds around, so I'm going to say it's the same one. This time I set up in a much better spot, with a decoy.
The hen (it's a hen, right?! obviously?!) obliged to show me very clearly she had no beard. I was a little confused at first, because she and her hen friend both fanned out their tail feathers like a Tom, in what I gather was an aggressive display at the decoy interloper. But as you can see I got a long, long look this time, long enough to get photos and videos. I was happy to see that my decoy and slate calling both worked so well. In fact I was chatting with her for almost an hour.
So, lesson learned. Even if I don't get a Tom this season, this morning was very cool, and I am learning a lot every day!