Ropensaddle - the only root that was above surface level (as related to this last pic) was the smaller one on the left that is circling right. You can almost see how much was exposed based on the coloration of the root itself (dryer looking brown, versus wetter looking). The rest were below the soil, but not that far down below, to be honest. It was the left root - and all the tiny surface roots that got me to wondering if something else was going on. However, I do have to admit, I don't believe I saw too much of a trunk flare before digging the soil out that exposed the girdling roots. If you go back to my original posted pics, you can see what I mean.
I would have to dig even deeper to determine what is going on with the two larger circling roots, but from what I can tell the 'top' one according to the pic angle does extend outward. The other I am not so sure about. I just haven't gone far down enough to identify exactly where they started from, nor where the second root goes. It seems to me that is a problem anyway, because - somewhat depending on where they both originate from - they may both have to go, as the top one seems to be secondary to the other one. That is what is confounding me so much about this.
I am contacting arborists in the area to come take a look at this. It seems like such a mess, that I think I need someone with the right tools and education to determine what all can be cut away. The problem is I've contacted 3 so far, and only one has even bothered to respond. Guess I will have to look for more. As much as I would like to resolve this one my own, I don't think I have the proper equipment to do so.