It is a Tex Tan Hereford, yes.
We took the saddle home for trial last night. It seemed to us like it fit up fine, but neither of us have much experience. We're having a friend come over today to check it out for us.
The horse rode around great with it. Even my wife let her break into a lope! (She usually is content walking and trotting, at the most) One weird thing was the first time I started trotting around, she coughed a number of times. But then stopped. It was weird because I hadn't heard her doing that before, but we've only had her for three weeks.
Hope these photos work:
Gullet (EDIT: not sure why this pic won't orient correctly):
We checked fit with our hand, and the only part that concerned me a little is that it seemed tightest right where the front of the bars land behind her shoulders. That may be evident in the first photo above. Perhaps I had the saddle too far forward in these pics? I followed directions from what I read online and what the saddle owner told me - set it on somewhat-too-far forward, then slid back until it seemed to "land just right" on her. I think the front of the bars were behind her shoulders. We had about 2 fingers clearance above the withers, and could snugly run a hand along the bars front-to-back. Saddle didn't rock on her, seemed to lay nicely.
Anyway, then we put on a pad and rode her for about 20 - 30 minutes, and she really seemed fine. We weren't running barrels or herding cattle, of course, but I got her to work up a sweat.
Also, we finally got to talk to her previous owner more last night. They had three different saddles they used on her, and unfortunately she didn't know if they were FQHBs or semi's.
I'm very open to hear what you guys think, if you can really say much just off the pictures and my description. And again, we're planning on getting an experienced friend's opinion in person tonight. Thanks for all your help!