FWIW I received my sight from Williams. It fits on the rifle very nicely. If I end up lowering the elevation very low, I might have to clearance the wood slightly. The issue I had is that the paperwork is generic and said a 6-48 screw came with the sight. I drilled the required hole with a #31 and tapped it with a 6-48. Then, lo and behold, the supplied screw is larger than 6-48! Fortunately one of the rear sight screws is 6-48 and I used it instead. Yes, it is my fault for not checking the screw but thought that might help someone to know.
The sight itself is much nicer than the 5D series I always put on my leverguns. It is also much cheaper than the TC or Lyman peeps are going fir on ebay.