In my attempt to learn more about the rifle, I met a great gentleman in Sweeden who was extremely knowledgable and was friends with, and contacted the owner of the Francotte arms factory in Leige and Masstricht. He did some research and found one german gunmaker that had lived in Ultrecht but aparently it was a very small shop as no other information could be found.
There is a mark on the receiver ring that shows through the stipping and at first we thought it might be an anchor (like the kreigoff mark) but will probably never know for sure.