Last battery shots for now: closeups of the positive and negative ends of the battery post-removal.
The back side of the board looks altogether better than the worst of what I shared here from the front side. There is little or no indication of issues in any traces spreading from the battery through holes.
Would definitely appreciate opinions and insights from others that have more experience than I do dealing with possible battery damage.
I can try testing continuity on traces. I could apply some solder mask and hit it with UV to cure where the little bits of copper are exposed.
I'm most curious if I need to sand or clean anything that presents more concern than I might know to have.
Lastly, I can hook it all up and just see how it works with diagnostic tests.