I purchased one of these knobs from our hosts (911-424-071-01-M350), along with the retaining sleeve (999-532-003-00-M100), but the shaft on the shifter was too skinny, so the knob was really loose. A half-wide strip of Mr. Grip solved the looseness problem (
Amazon.com: Woodmate 2498 Mr. Grip Screw Hole Repair Kit: Home Improvement). I put the retaining sleeve around the shaft of the shifter, slipped the 1/2-wide strip inside the sleeve, then wedged the knob down over the two, nice and snug. In fact, it might have worked to just use two Mr. Grip strips instead of the retaining sleeve, saved a few $$, but I'm happy to have this working.