Vintage refers to this same time period. Used is anything pre-owned that was made since then. Y ou can also make use of both old and more recently produced paper items and ephemera for hardback shades. These can be put to use either in their original form or copied. There's more about this in the Making Hardback Lampshades section.
T here are other things that can be incorporated into shade crafting, too.
If you don't want to go into this as a business or give lessons in how it's done, you may want to get inventive with your reasons for wanting their old shades. Put up signs on bulletin boards or put a want-ad in the newspaper. See the idea above for the problem with this one. Keep an eye on the side of the road for thrown-away shades. I've found lots of them this way.