37mm ID

[fert]

Hello
I m looking for right ID this 37mm. No markings except for 31
My guess is for bofors at gun Polish or Romanian made.
I saw Polish HE shell but longer than this. I’ve never seen real Romanian one.
Anyone could help me?
Regards

 

[greif]

Your shell looks like Fig.1: 3,7 cm Sprenggranate genannt Selma. Unfortunately no dimensions are given. The drawing is from a Solothurn brochure : Beschreibung der Munition der 3,7 cm Tak. Someone told me these guns were also sold to Hungary.