I am trying to determine if the Hurst shifter in my '69 Z/28 is the original one that came from the factory or not. The handle is riveted to the shifter rather than bolted. On the shifter it says: Hurst Competition/Plus, has a number, 128D11C stamped on it, and the following US patent number, 3216274, also stamped on it. I am thinking that this is not an original shifter that was installed at the factory but would like to know for sure. Thank you.