Aha!! I just checked Ebay here in the states, and Wannsee is also listed here! (Although it looks as though their ad has been automatically translated to English, so I dunno if Ebay is just listing international sellers now. I'm not really an Ebay expert...) Thanks, I will give them a shot!

EDIT: Just got a confirmation note, written entirely in German. So I'll hopefully be able to test out Polarcell myself in a week or two...