A colleague found this wall painting. We are sure about the elements related to mining and the divining rods. But we've got no clue for the spiral element that seems to be operated/carried by two people.
For dating we've got a hint at least. There is a particular kind of bird in the painting, maybe the "Northern Bald Ibis". They nested in the cliffs, and on castles and ruins in the Graz/Steiermark and Salzburg regions of Austria. They got hunted and vanished around 1630-1645, as their feathers were used for hat decoration (plume hunting). Thus, the painting should date around that period.
Location: The wall-painting was found in a celler of a patrician house in Graz.
Can anybody help out?