A fellow named Jed McClure assembled this hex map of Poland, including descriptions of every settlement mentioned in the canon books (I don't know if it includes material from Challenge Magazine). It's a nice piece of work.
http://www.jedmc.com/ixdd/2014/1/8/a...h-sandbox.html
It's been a while since I looked at it, but it might be of help to you. I am unfamiliar with the region that you mentioned. Northern Poland is my stomping grounds. The only Poland campaign I ever ran followed the Vistula from Krakow to Grudziadz, and the one I'm playing in now is set in Gdansk, and the module that I wrote focuses on Malbork and its environs.
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