Something Borrowed, a Vintage Rental and Eco-Event Planning company in Portland, Oregon, have created a national directory of vintage rental businesses. It's a great resource, and interested to see where these boutique rental businesses--most of them very new--have popped up. California is out front, so is west Texas. There's a big hole in the West and Southwest and Western PA, coastal South, etc.
I'm happy to see Nimble Well on the map in Chicago providing unique rentals for Chicago couples looking for cake stands and other rentals to complement their wedding style.