I believe you must have gotten your info from YOOPER JOHNS web site. TULA stopped sks production in 1956....... the crilliac A and REVERSED N are 1955/56. K after ser# is accepted as being East German. other Russian firearms produced AFTER 1956 had the crilliac N and A stamped on them,hence the confussion about a 1957/8 SKS . hope this helps. the sks you posted is a 1956 model.