The home that I'm in now was built in the early 1950's. Although the studs seem to be on 16" centers, the framing on either side of every door and corner is a 4 X 6". I had wondered why the light switches were so far from the doorways until I had a bathroom replaced and got to see inside the walls. My son's house, across town from mine, has the 4 X 6" corners, but the wall studs are on roughly 20" centers. He is totally rebuilding the inside of his house, so many new pieces of wood have been used in the walls. There wasn't much building-to-code around here until about 1980, so any home older than that is full of surprises. He discovered that the crawl space walls were only 1 brick thick too, and no footings. Evidently the house had no foundation to start with and it just sat on posts. Then they closed it in later, making it look like it had a full brick foundation.
He got the land with the house and metal 40 X 60' shop for about the value of the land. I had told him to push the house down and start over, but he insisted on remodeling it. He is paying for the rest in labor and replacement costs now.
Charley