Who gave it to them? Was it the same person who did all the other birth announcements published that day? Why else would all the birth announcements in both papers be worded the same way and for the same dates?
Most papers do NOT automatically post birth announcements. Some people may not want them in the paper. You give them the info, they print it.
We're talking 50 years ago, it was far more common. Even today the local paper prints marriage announcements, divorce announcements, and births. They get them from the city government.
Explain the address. I’ll wait. Go do your research and come back and tell us who lived at that address at that time.