Mercedes vent window knob- 1117605266 and cap- 1117600567 for models of the late 60’s.
Be sure you are getting the correct cap because the chrome ring is thinner than the early version which is shown on the left in the photo. You are getting the cap and knob on the right

The diameter of the knurled knob is over 2 inches, about 54mm. The metal shaft is also longer at 3/4 inch than the early shorter version. The thickness of the knurled edge is 1/2 inch.  I also have just the knobs in clean condition. Ask for details.