world war one - What's this 1917 shell casing, more exactly

I've been gifted this vase that is obviously made out of a large shell casing. It has 'MARZ 1917' stamped on the bottom, plus other less understandable markings: 'St', 'G', '36', 'HL 25'. I'm attac

18 pdr shell case-markings - Arms and other weapons - The Great War (1914-1918) Forum

1917 Ww1 Trench Art Shell

world war one - What can I learn from these WW1 shell cases? - History Stack Exchange

World War One Trench Art

564 Ww1 Munitions Stock Photos, High-Res Pictures, and Images - Getty Images

world war one - What was this 1917 shell casing used for? - History Stack Exchange

This Explosion Was the Biggest Blast Before Atomic Bombs

Diagnosing Shellshock Amongst Men & Women in WW1

Antique Shell Casing

WW1 Trench Art Artillery Shell Vases /b

Polte WWI 75mm Shell Casing - General Ammunition Discussion - International Ammunition Association Web Forum