Both type knobs fit the same size shaft. A 67 should have the set screw in its wiper knob. They did delete that set screw years later. The later knob has slots where tempered steel tensioner was slid in. And that little piece could fall out when the knob was removed from the switch shaft.
I'm sure one of our members would have the correct knob for your car. In fact, I may have a nice extra here somewhere.
