Kriegsmarine Torpedo G7 a submarine fuel / spirit canister 25L for torpedo

Original Kriegsmarine spirit / fuel canister, 25L, for powered torpedoes, e.g. the G7a torpedo.
Good condition with no rust through. 
 
A rare piece of naval history directly related to the torpedo weapon. It was used on the submarine as well as in the torpedo arsenals, or TVA's.
This canister here comes from a private estate.

This is probably an early war version, probably the so called "full bronze" version. Material seems to be kind of copper/ bronze.
Some of the bronze was replaced later by aluminum due to material saving measures (large hexagonal screw joint with the vent screw), the last ones then by steel.
The aeration screw needs to be made common again, the spout opens and closes loosely. Stampings so not found.

Item condition: used, original