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 attaching a photo, of course.
The diameter of the largest part at the bottom is 90 mm, i don't have a caliper but by measuring the 'lip' i think the actual tube is 80-82 mm wide at the bottom and 76-77 mm at the top (it's been deformed by the beautification process).
It's not a matter of life and death, but it would be fun if someone could shed more light on what those markings say.