There is no source I know of. You have to collect catalogues and look for the first time you see a style in a catalogue. Sometimes it will be labeled as new. Style 9929 was in a 1993 catalogue but I don't know how much earlier it went into production.Is there a source to tell when a bag style (i.e., 9929) went into production? I think it was the early 1990s, but would like to be sure