Some addresses of merit when searching for older instruments: www.roguemusic.com www.ugbm.com http://caruso.net
These guys offer fair warranties on old gear and the service has been good. www.musichotbid.com www.ebay.com/
With these two, just be mindful of the tendency for auctions to spiral out of control, pricewise. Then again, you might find a real steal.
Don't ignore the local want ads, either; people sometimes ditch things for a song because they don't know or don't care what they have in hand.
Also, pray heavily and promise God things you have no earthly hope of delivering. If He likes your style, His connections are said to be extreme.