Hello Bahner I dont fully agree with you.
My Norwegian book do not cover Trondheim - that city is in volume 2 and I dont think that it is published yet.
The mark of June 22nd until July 22nd is 69 turned 45 degrees.
I was thinking of the mark of the Lion July 23rd until August 23rd - but it's not real right.
I also think that KM is the maker. The assayers mark is more likely to be the other one.
![Image](http://sv1.letmehost.com/sv1/24/thumbs/IMG_9733_b.JPG)
These marks represent Christiania (Oslo) left page is guardeins marks (assayers mark) 1719-1741 left top and 1867-1880 bottom right.
Right page is month marks March/April top left to February/March right bottom.
Most likely the Trondheim marks follow the Christiania marks - and Christiania marks followed the principle from Denmark/Copenhagen.
Regarding date I fully agree with you.