Congratulations on your new acquisition! And thanks for sharing!
Your rifle has National Match features, such as a polished bolt and receiver runways. However, no documented NM rifles are known to exist around your rifle's serial number at this time. And the barrel date is a little on the late side for a NM rifle. And the polishing on your rifle's bolt is not quite consistent with an NM bolt.
A more likely explanation is that you have a sales rifles which the owner upgraded to NM specifications. One had to be a member of an NRA-affiliated shooting club to purchase a sales rifle. So the purchasers were, by definition, avid target shooters.
Thanks again for sharing! And congratulations again!
J.B.