Thank you Hose_dk for your insights. I am now nearly 100% sure maker is ‘TORNBERG’. Since deciding the maker is Tornberg I found an auction house selling nearly identical spoons as marked Tornberg, Linköping from 1811-1833. Is it possible the city is Linköping not Norrköping?
Linköping might make some sense as my family is actually originally from there (a long time ago).
Marks on the spoon in question falling into place…
http://putfile.com/pic.php?pic=5/14913202786.jpg&s=f5Thanks to all who have had a look.
Best regards,
Ernest