I don't have time to research links, so, when I give you sites to check out, just put the words in quotes on your Google search bar, and you have a shot at finding the place.
For people who might give you one or give you info to find one, try:
"Freecycle Network"
"Craig's List" + trade (if you have something to trade for one)
"Craig's List" (they have so many, I can't imagine they don't have one for gathering info, or even finding old antique gardening stuff)

For folks (find the "Contact us" link on their sites, and ask) that have enough info to, at least, tell you were to look:
"Garden Decor' Specialists"
"Outdoor Antiques"
"Antique watering can"
"Estate landscapers"
"Junk yards" (hey, don't knock it -- I can't imagine people don't just through them out.)
e-how.com
"Homes and Garden"
"P. Allen Smith"
"Victory Garden"

OK, gotta quickly ask my question before dinner. If none of those pan out, just reply again on this thread. I'll set it up to forward me e-mail, so I can look for ya.