Nuremberg rathaus layout?

I'm looking for a floor plan or similar of the medieval wing of the Nuremberg old town hall. I know the main hall runs the length of the building, but what are the rooms off it? That is between the ceremonial hall and the courtyard.

Also, what did the rose window of the original facade look like? I've seen a small version of a painting by Juvenell which shows it, but it just looks like a blue blob. The only other image I've seen is a sketch of the original facade which also shows the houses that once overlooked the Rathausplatz.

I'm looking at doing a model of the building as it might have appeared in the middle ages.