5cm case mystery

[SG500]

Hi all, attached a few photos of a mystery case. I've looked in the books and can't spot it.
Could well be a cut down but if so was done a long time ago and is very well done.
Possibly a depth charge case?
Looks a lot like the bottom end of a 3 pounder case but the rim isn't quite right for that (I don't have one to compare).
Length 159mm
Rim 62mm
Mouth roughly 52mm (slightly distorted).
Any ideas who made it and what its for?
Thanks.
Dave.

 

[doctor]

SMI Societa Metallurgica Italiana

 

[SG500]

So.......possibly a cut down Italian 47 x 328R anti tank that has a rim of 62.2mm.........but it looks like an anchor on the head stamp?

Its the only one on my list that gets close.

Thoughts anyone?

Dave.

 

[Hoeksel]

Checking my references based on the rim diameter my guess would be 47x328R62 for the Italian 47/40. Maybe adapted by the navy, post war, for some depth charge thingy or salute?