Hello Everyone -
A contributor to the component dating page of the Vintage-Trek.com site, Ben Weiner, pointed out an interesting resource concerning Shimano components:
It gives the years in which particular Shimano component models were sold. (Unfortunately, it only goes back to 1980. :-(
These pages were assembled by the Specialized Technology Committee of the Allgemeiner Deutscher Fahrrad Club. Yes, it is in German, but year and model designations are effectively in English. If you like, use the web site translation function on the AltaVista.com web site.
There also is a section on Campagnolo components and parts, but it goes back only to 96. However, the good news is that it appears to be a work in progress.
in (temporarily) Sunny Renton, WA