Bronze Mortar Model Marked "1530"

[cannonmn]

This mortar barrel model is marked "1530." It is bronze. Bore is two inches, total length is nearly eight inches. It belongs to a friend who has asked a few questions:

1. What nationality is this piece?
2. Was it cast in 1530?
3. What was the purpose of this model?

He provided the engraving shown, without whatever caption it may have had. You can see that the large mortar on the right has a similar barrel with "rocker" base and protruding stud whereby the mortar is elevated with a winch.