Since the arsenal that manufactured that rifle only produced Type 38 rifles until 1940. THe metallurgy of the Arisaka rifles are GOOD until about 1942 where they began to sharply decline in quality.
http://www.surplusrifle.com/arisakatype38/index.asp
world of information about the Type 38 rifle, including how to strip and reassemble it.
Now that you know what type it is, when it was made, etc. Getting it to a qualified gunsmith to inspect is now a easier task.
A picture of the markings on the center of the reciever (close up) would aid greatly as that is where the Japanese wrote what type of rifle that is just for confirmation. Also, when holding the rifle from the stock end, the type markings are read right to left.
EDIT: as i stare at those pictures more, i am doubting the identification without reading the code itself. The Type99 and Type38 both had identical arsenal/serial number combinations for the Kokura Arsenal. If its a Type99 then the manufacture date is probably closer to 1944, so the importance of that center reciever mark now is very important.