Help I have recently obtained a few items but this one stumps me unmarked driving bands but wide apart shell measures 73.88 mm across the base and 77.21mm across un marked DBs and is about 1850mm from base to top. Top is what looks like flattened lead cone but has bee sugested as lead fill to give it weight I can find NO markings anywhere on it. In the same lot but not attached was a 3inch naval shell case in steel still carefully wire brushing to find full info.