I wonder if the carpenters of the pre WWII era didn't build some pretty fine homes, square, level and plumb. One old codger that taught me always made a story stick. He would go around from corner to corner checking heights. If the top plate is not level and square, you can be the roof framing will be a challenge. And so on and so on.
But, as mentioned, the old gals do tend to settle a bit.
