Anime-Link and Usagi's House get hanken 
sometimes, but
they don't put them for sale on the Internet...for 
instance,
Anime Link had a Tenshi ni Narumon hanken 
mono (one used for
a pretty common telephone card, actually...)  If 
I were looking for hanken,
I would definitely try Mandarake's auctions.  
They now have a system where
overseas bidders can bid in their 
superfantastic cel auctions...you have to buy a
catalog, which is expensive, but the cels at 
auction are GREAT.  Hope you
find what you're looking for!

Gaudiora