I amazed you didn't want us to front you the money and buy them for you too.
The recliner knobs are the same handle knob that the manual front to back adjuster handle in the front of the manual seats would have.
GM part number 9834636
Here's the tricky part. They come in 2 styles under the same part number. The original style from the factory are the smooth ones. The other style with the same part number comes with a textured finish.
So whichever you go with, match the 3 together if you have a manual front passenger seat. Or 4 if you have a manual driver's seat (non-power).
Eckler's sells the textured aftermarket versions.
1968-77 Black Bucket Seat Adjustment Knob
www.ecklers.com