The producer marks are usually the serial number and the supply mark, more rarely the romantic initials of the owner. The supply mark identifies a certain supply (of torpedoes, tubes or compressors), it is composed of a letter standing for the nation (N for Norway, SV for Sweden, A for Austria, Ar for Argentina and so on) and a number referring to the supply itself. I don't have documents to identify the torpedo from the serial number, but here some considerations that might led to a very likely guess:
- Your serial number (5647) falls in the year 1897 and doesn't belong to a Swedish supply, just to cut off the next best option.
- 55x450/3,68 torpedoes were supplied to Argentina, Brazil, Norway and Japan between 1893 and 1897, I don't know the exact date for each supply.
- During this window of time, deliveries under different batches from Fiume to Norway happened on three years: 14 units in 1893, 23 in 1896 and 39 in 1897, among these 76 torpedoes 34 were of the above type.