I've got a WW2 shell case and I'm wondering how much it's worth. It was given to my grandfather when he was a ship pilot by an British man so I'd assume it was English but he sailed everywhere so it might not be.
The shell case measures 80mm in diameter and 130mm long and I could only find examples of the little rifle(?) ones on the internet.
On the bottom of the shell case it says:
12PR12CWT (underneath that there is an 'I' and an up arrow)
RL (and then B3 in a little diamond)
N (underneath which it says'1940')
LOT 168 (underneath which there is a little hexagon that contains the letters 'PM')
Sorry if that description's too vague! I'll try and post a picture if I can.
I'd really appreciate it if someone could help me to identify it and tell me how much it's worth.
Thanks in advance!