Thank you everyone! I appreciate your expertise and apologize in advance if I use incorrect terms, I am new to this. The tang reads "Shibayama Kaneyasu 柴山兼保" so I'm assuming (correct me if I'm wrong) that this blade was made in Shibayama, Chiba. Would Kaneyasu be the actual maker? I couldn't find a WWII-era sword smith by this name so wonder if anyone has an index of period makers. To my novice mind this is a “Type 98” Shin guntō circa. 1938-1945 but your expertise would be invaluable. The scabbard is bamboo so I'm assuming it was produced late in the war when Japan was running out of metal.
What concerns me most is that the blade might be older as I've seen the name Kaneyasu pre-Meiji. I realize that the new military swords made for WWII may have included older blades owned for generations for officers. Could you look at the blade and tell me if it's WWII-era or a lot older? Thank you for your patience and help. It is much appreciated!
Teddy