Looking at buying a swedish mauser M96 made by Carl Gustaf. One I am looking at does not have a manufacturer date stamped on top of reciever between the barrel and the chamber. The other I have looked at do. The serial number is 419547. Wondering if you could identify the date it was manufactured and why it is not date stamped Was wondering if it was reworked later in its life. The manufacturer name is on it, just not the date. Please advise.