I have found and am interested in purchasing a Model 99 EG, serial # 846XXX. I'm told it has an approximate DOB of 1953; should there be matching serial numbers on the forend, stock, and butt plate? The only marking found are possible assembly numbers as follows, forend marked "NM" with a "18" or "I8", the butt plate is marked "NM" 17 and what appears to be "207" stamped separately. Are these markings correct for this age rifle? Any help and info you can share with me would be appreciated. Would hate to pull trigger on a purchase of a rifle that has been pieced together. ???