What is this?

Got two of these at local market. Original owner couldn’t shed light on what they are. Length is 196mm. Fits a 37mm projectile perfectly. Base diameter is 56mm. Been all over it with magnifier & can’t find any markings. Any country renowned for not marking their brass??? As I am in Australia, am thinking Japanese but have Japanese cases with markings. Won’t let me put up pic of base

Looks much like a 42mm Nordenfelt. Can you post an image of the headstamp now?

It looks like a 1.5" Heavy Nordenfelt navy case.
Should be 38x197R but the base is around 52.8mm and the rim is 59mm (not 56mm)
This means it may be some other case .
42mm Nordenfelt has a 62mm rim. (42x260R).

Ron maybe it is a 38mm.
But the 42mm is not 260mm long as far as I know since the 42mm is a 42x196R no? (next to variants a few mm shorter)

Absolutely no headstamps which is why I am stumped