Welcome to the forum.
I am in the process of making one. I took the selector knob off and found a piece of thin PVC that just fit over it. Then I heated it with a torch to soften it, and used a tool to form the softened sides of the PVC around the knob contours for a tight fit.
Next I need to add a larger piece of PVC to the other end, with cutouts to fit the 'raise and lower' knob.
Maybe I should paint it and put it on eBay
Family of six, camping in a Grey Wolf 26DBH LTD pushing a 2010 Armada via 10k/1k HaulMaster WDH stopped by a Prodigy P2 brake controller
Tug: 2010 2wd Nissan Armada Titanium with tow package.
Specs: Max Trailer Weight 9,100, Tongue Load: 910, GCWR: 15,100, GVWR: 7,150, Payload: 1,592