You posted two pictures of the same (shield, or mark) side of the knife. Do you have a similar picture of the other side so we can see the tang stamp on it too?
From your description It's probably what is called a "transition" knife. This is one of the few patterns having two master blades. The knife would have been made in 1970 but there were some left over blades from 1969 so during the transition from one stamp, XX U.S.A. to another stamp U.S.A. with 10 dots, the knife got assembled with one of each. Not uncommon, but some will pay more for those knives.
Picture of the other side would confirm.
Welcome to AAPK.
Edit: looks like you were posting the other side at the same time I posted my response.
Yes, that's a transition knife, as I described.