Hello again and there is my second mystery headstamp : The shell # 200-5 is 12 3/4" high and the outer diameter at the headstamp is 64mm. The best I could find is Svenska Metallverken A-B. Am I in the right direction?
Sansaner
Made in 1889 by Société pour la Fabrication des Munitions d’Artillerie, Bas-Meudon, France.
Regards,
Fede
Jeez, I measure my ignorance. Thanks, it makes sense because the shell is decorated and heavily varnished Here is the 
photo
Sansaner
This is one of the very few cases converted to trench art (even if not made in the trenches or by soldiers) which is a real art piece.