I built a website, consisting of over five hundred pages of information, so far, designed to help people, like yourself, better understand the world of vintage road bicycles. The website,
MY "TEN SPEEDS" should answer most of the kinds of questions that you are asking.
To best begin your journey through MY "TEN SPEEDS", I suggest that you begin by learning
how to determine a quality vintage road bicycle from those of lesser pedigrees.
I hope this is a help and good luck finding your way through this very interesting activity.