So, the Mohawk would be a 1980. They didn't start making them until the late 60's to early 70's.
The 700 is likely a 70's rifle. From the start of the model 700's in the 60's, and pretty much through the 70's there were no letters on the serial numbers. I have a 700 with 6**** serial number and it is a 1974 rifle. I'm clueless on the shotguns though.