There's always ebay and...
American Science and Surplus - We're lucky to have their store in Milwaukee but they have a website/online store:
http://www.sciplus.com/
(click under lab supplies and equipment)
Their stuff is new, so you'd have to "antique" it yourself by using tea and brown paint/drybrushing to make the stuff look old - but it's pretty affordable.
Their website is fun to look around on - LOTS of weird stuff.







