It's big, and I don't know what it is

[tinhat]

This is quite big (compared with anything else I've got!) It's 63cm long, and about 80mm in diameter. The head stamp says SMI 7506 and DIS 18871/E and some other stuff which you might be able to make out. Due to its size, it's going to be decluttered - when I've found out what it is. Then it'll go on Classifieds. Grateful for any help.

 

[2pounder]

looks like 76mm Otto Melera Italian navy modern.

 

[tinhat]

Thanks for that. I bought it at a flea market in Normandy a couple of years back. Now I know where to look, I'll see if I can find out more about Italian stuff.