Hi Michal,
Thank you so much for taking your time and posting all this awseome stuff from the Krakau National Museum, thus making it finally accessible to the rest of the world!
Please let me comment on a few early German firearms in the Krakau National Museum in which I am highly interested in personally.
1. A South German tiller haquebut with what seems to a be a (Nuremberg?) octagonal cast copper alloy (brass or bronze) barrel, ca. 1480, of switching sections, the touch hole on the upper flat section, the heavily swamped muzzle section again remarkable for featuring a pointed upper section which simultaneously acts as a foresight.
Best wishes from Lower Bavaria,

Michael