ANOTHER POINT - If it was routed for a coin inset about the size of a nickle, the it is at least 70-73. Someone will correct me if I am wrong, but I think Bear startred with the raised plastic madallion in '74.
The worst thing Bear did to us was to get away from the Serial numbering system that was used in the '60's. That made it really easy to tell the year. While Frank Scott was still around, you could call the Bear Museum in FL and give him a serial number. He would call back within a half hour and tell you the year, and any other info they had on it. He was a super guy. After he passed away, no one ther knew how to look up the info. And of course, now, the Museum is no more. WHAT A LOSS!!