Can any one help with this one, it has SPRA 3/38 IXN and a diamond with sv inside. I think it is made by Schermuly Rocket Pistol Apparatus Ltd and may be some sort of flare, perhaps for landing aircraft. it has a test tube shape body(nothing inside)with two small pips at the top which locate into the small brass cap which twists off. it looks like it threded into somthing else, maybe an outer body?it also has two small flats for a tool/spanner.