CHINA. Shansi Arsenal. 2 Fen, Year 17 (1928). ANACS EF-40 Details, Chopmarked.KM-Tn2; CCC-667; Duan-3470. Though ANACS calls this piece chopmarked, they are referring to the two punches that are indicative of this issue.ANACS EF-40 Details, Chopmarked.