Hi guys, I picked up a couple of SKS rifles and I was just looking for a little help with dating them and factory information. One is Marked triangle 316 serial number 18000XXXX and the other does not have an arsenal mark but marked 8 - 15150XXL followed by a triangle with a smaller triangle inside. I?m not sure how old they are by using the formula 55 is the starting date I?m guessing 1970 and 1973 perspectively. Am I wrong? One has a beautiful red laminate stock and beautiful deep bluing. I paid 1025 for the pair. Any help you guys can provide I appreciate. Both are all matching numbers so I was happy to get them. I wish I could post pictures, but I can?t get them under 350 kB.