These are built from recycled 1540's short Landsknecht arquebuses barrels, assembled and mounted in the 2nd half of the 17th c. (Baroque period).
The top barrel with its heavily swamped and widely flared muzzle is even as early as ca. 1480!
For a perfectly preserved Landsknecht matchlock arquebus of ca. 1540, the barrel with identically incised vertical lines at the long muzzle section, in my collection,