Shell casing from World war 1?

[warhammer]

Hello, I have been having a hard time getting an Idea on this shell casing, My great Grandfather fought in France and was either a tanker ( the loaned out British Mk IV to the U.S. ) Or he was in the 161st which was assigned to the 41st Division, composed of National Guard units from Washington, Oregon, Idaho, Montana, and North Dakota. They were sent to various units as replacements.
He brought home a varied selection of items Please see this link for high definition pictures.. Thank you so much.. Jeff http://imgur.com/a/3Fo3w
these are more of the collection that may help solve the casing issue. http://imgur.com/a/52r1i

 

[Alpini]

your case is italian and originally meassured 75x278R. It was used in the Cannone da 75 Modello 906 (1906) which was a Krupp gun built in license in Italy. Some of these guns were captured by the germans and converted into improvised anti aircraft guns. That's the only explantation to me if your Grandfather found this case in France (Italian cases are not very common in France, but there are many more possibilities where he got it...)

917 = date of manufacture = 1917
SMI = factory = Societa Metallurgica Italiana
MODo = abbreviation for "Modello"

 

[warhammer]

Thank you so much... He was a mystery and a man of wild adventures. His Dad had a great collection of American Indian Relics which were stunning in both quantity and quality.. I am in charge of selling the estate so I continue to learn.. I really appreciate your time.. Jeff