tang sight
I have seen a tang sight in Brownells catalog, it shows a tang sight by Marble, stock #579-009-811 for the 66 Uberti or Cimarron, #579-000-002 for the Henry, and #579-000-003 for the 1873 by Uberti/Cimarron. The price is $125.00. As only Uberti makes these rifles, it really wouldn't matter who the distributor is, Navy Arms, Mitchell, etc would all be the same. As nearly identical as the Henry/66 and 73 are, I imagine the different stock numbers must reflect a slightly different tang screw size or location on the three rifles. One of the screws (the front one) might need drilling and tapping the tang. The Henry already is, and some 66s and 73s might be already tapped. I did try a 73 sight I bought from Taylor's on my Henry, and the screw holes didn't line up (and no way to drill a new one, as the Henry was factory pre-drilled), hopefully, the Marble parts with the appropriate stock number will.