I did many title/registration searches on COPOs years ago. It was easy then; send a few bucks, they sent as much info as they had. But even then few states went back to the first registration. 10 years was max, many only did 5. Some states didn't issue titles in the '60s; some states registered cars by county. New privacy laws have closed the books and it doesn't matter that much as no one keeps records for 40 years. With a few connections at one time you could have a law enforcement officer do an NCIC inquiry on a car to learn where the MSO was issued. That has also become more complicated and does not always produce results. Short of plain old luck you may never learn anything about your cars' history.
Transmissions seem to acquire the names of their city of manufacture; Muncie, IN or Saginaw, MI.