I found this in my own town, and it is available for me to procure if I desire. I think it is German as I removed a C12 primer from it with no date. Strangely, there are no markings on it at all. Dimensions are approx. 170-180mm wide at the mouth and 1040-1050 mm tall. What is it, and what is it worth? My current best guess is a German WWI 170mm naval gun. Thank you for your help.