Michael thank you so much for this update and photos! Artillery has never really been one of my fields of study, but on many occasions I have had the opportunity to learn a little from events much like this. I recall in California years ago when several cannon washed onto the beach near Goleta. For some years afterward there was a great deal of furor over what nationality these were, and even suggestions they may have been Sir Francis Drake's.
I believe eventually it was discovered they were much more recent, but the course of research was fascinating.
I was inspired by your entry here to seek more on the cannon from Swedish ships of this period, and naturally the most prominant example is the amazing recovery, restoration and display of the warship 'Vasa'. I found interesting notations etc. but as yet could not find the wonderful line drawings often shown which depict the often amazing detail in producing these powerful weapons. In the search I did it reminded me of how extremely important such ordnance was in the warfare through history, and how much you yourself have done to study, learn and preserve that history.
You truly are the ordnance master and steward of its history!
Thank you so much Michael!
All best,
Jim