Japanese Capture Enemy Rifle Shell Casings, Chopstick Handles

Original era manufacture. An interesting lot of four .30 caliber brass shell casings, each with a set of different (to my eye) hand engraved kanji on the side, each with different markings on the base of each casing. What I believe these are, are captured enemy casings; German, Chinese, Russian and so on, which were converted into trench-art chopsticks, with the casings used as the handles. Each of the casings has had a 4mm steel rod inserted, which has been cut-off at the top of the casing for some reason. We had a complete set of these for sale several years back, which were produced from captured Russian casings from the Russo-Japanese War. Sold as a lot.