Hello, I was just wondering if anyone could tell me what the rusty old projectile in the attached photos is ? It is 335mm (13.2 inches) long, 92mm (3.6 inches) wide at the base, and 60mm (2.4 inches) wide at the top. It weighs 10kg (22 pounds). I thought it may be an old 25-pounder HE projectile ? Thanks in advance.