Here you go. I have one on a 12" WT clone and it's smooth and accurate. Better than the ones on my Jelco 850s.
https://www.ebay.com/i/112656194867?chn=ps&norover=1&mkevt=1&mkrid=711-117182-37290-0&am...
https://www.ebay.com/i/112656194867?chn=ps&norover=1&mkevt=1&mkrid=711-117182-37290-0&am...