I don't think the aging on such changes will be close enough. It will get you within a decade. Various manufacturers adopted changes over time, rather than overnight. Look how long it has taken to make the move from 27 inch rims to 700c.

I have modern bikes without FD braze-ons, and older bikes with them, from the same manufacturer.

Best way to date a frameset sometimes is to just look for a code on the fork. Many forks have date codes on the steerer tube. And if the bike has any original components at all (bottom bracket perhaps), they are often date coded as well.

You will see people postings on here often wondering whether their bike is a 1982 model versus a 1984. I have never understood this quest. On most bikes, there is no difference in value. I wonder what they do with that information?