First Cardinal Rule
Regarding vintage anything; usually want one wants will not pop up in your local area! lol!
For larger items like vintage appliances this can be a problem as shipping is a bear. However check out Craigslist.com if they have a site in your town/area. Next hit estate sales/auctions in your state. Also keep an eye out for homes being sold. With house prices going sky high, many seniors are cashing in by selling their homes. While appliances usually are sold as part of the house, you may be able to purchase a vintage appliance under the theory no body would want old "junk". The key is not to appear to eager, a savvy seller will catch on and begin to see there is "gold in dem dar hills", and not strike a good deal.
From my own observations, seems most vintage washers/dryers come out of the Mid-West and North-East. Gleaned this by just browsing Fleabay and seeing how many vintage appliance auctions are always from those areas. Guess as another poster stated, homes there have basements to store old appliances.
Launderess