I’m going to stir the pot on this thread.  As much as I respect Yearout’s work, I don’t see how these sights could have been made by Sharps.  Sharps went out of business in 1881 and the sights listed in the Winchester catalogs of that time didn’t change.  

I have started collecting Winchester sights and marvel at their high quality and how well they work, well over 130 years later in some cases.  

Some nearly identical sights show up in other rifle manufacturers catalogs of the period.  The Bullard catalog of 1885 shows virtually identical sights to those listed in the Winchester catalogs of that time.  The woodcuts even appear to be the same and the sights bases even say W.R.A. Co.  See “Old Gunsights” by Nick Stroebel, page 152.

Marlin had some similar looking sights but also had some that were different from Winchester.  For example, the Winchester Rocky Mountain front sight first shows up in the 1884 catalog.  I don’t know when Marlin introduced their Rocky Mountain front sight but the base is different from the Winchester sight.  Also, the blade is much larger and is contoured to a “pin & ball” profile while the Winchester model is a plain blade.  In later years, Winchester made the blades higher or lower for different rifles and caliber combinations.  In any case, the Marlin model of that sight is very different than the Winchester.  

Other possibilities include Remington.  I suspect it was one of the smaller machine tool companies such as Providence Tool Company or Bridgeport Implement Company.  Maybe more information will come to light.

At least it’s nice to have a topic outside of politics to discuss and debate.