A Modified Japanese M1902 otherwise known as a Papa Nambu.  This was an improvement of the M1902 which is known as a Grandpa Nambu.   The Papas were used primarily by the Navy and  were exposed to salt water and salt air so they are typically found with a lot of finish deterioration.  This is one of the nicest I have observed and is also a very early one.   This example was made by Tokyo Gas and Electric who produced the first Papas.  The Tokyo Arsenal also produced these guns and picked up the serial numbering where TG&E left off.  Some early Papas have a shoulder stock slot like the Grandpas but on most Papas, the stock slot was filled as you can see in the next to last picture.  It's hard to find an example without major pitting on the grip straps.