Vintage and Used Traverso Sources

Here are some places where you can find antique and used flutes for purchase.
Tony Bingham, London
Tony is a leading dealer of antique flutes in the UK.
William Petit
A leading French dealer of early flutes
Von Heune Workshop
They have a very good selection of used copies, and a few antiques. Give them an email or call to see what they have around.
Vintage Instruments, Philadelphia, USA
A large selection of vintage flutes, mainly cheaper 19c instruments.
Lark in the Morning, USA
Also a large selection at somewhat higher prices than the above. Here is the actual list. Note this store had a bad reputation for customer service but Mickey sold the store a few years ago, and the new owners appear to be better.
eBay has a wide range of flutes up for auction if you don't mind checking routinely. They vary from complete junk to great finds. Here is a good search to get vintage flutes and not much other junk.
Hobgoblin, UK
Early Music Shop, UK
They primarily list used modern copies.

If you are interested in antique flutes you may also want to consult Ardal Powell's on-line Database of 18th-century flutes, which is very extensive.