Ive had this rifle for about 30 yrs and finaly trying to date it. It was made at Nagoya arsenal but the series stamp matches none on the chart. It appears undamaged. In fact the bolt and so forth were still packed with cosmoline until 2 weeks ago when I cleaned it,back then I thought I`d leave it that way for collectors reasons but you know how cosmoline does. Attached is a photo if someone can help.