Unless the picture is deceiving it Looks like a thick based Tang sight for the 76 as you said. Having that stamp on the spring means a lot IMO! The base would be approximately 3/8 thick or 0.375 in thickness. Looks to possibly have the marked graduations on the left side of the staff. Graduating from 1-3 and in 25 marked increments (0,25,50,75,1,25,50,75,2,etc............3) Pretty sure this was offered as an option and possibly in a velvet lined moroccan leather case with a Globe front spirit level sight and additional inserts. Very nice desirable and harder to find Long Range Tang Sight.
HS 58
I Learned a long time ago to Separate My Want's from My Needs!
Yes, last night I saw a Win M1876 with shotgun butt that had one of these sights mounted on the upper tang. It does have graduations on the left edge, but my photos don't show this as well as desired.
Been thinking more about the sight you have and in looking into my information the aperture disc you need would have serrations on the edge like a coin for better grip as you rotate it clockwise it tightens. Clockwise to loosen it for yardage adjustment. The Winchester Long Range Vernier Tang Sight was a first variation as a #36A in the 1878 Winchester catalog and discontinued later in 1932. The #36A having the thick base and the #36B having the thin base. The earlier having the exposed spring for the Henry Rifle and model 1866 and also the early 1873's. Yours having the Spring under the thick base and stamped for the Model 1876 was similar to the ones stamped 1873 and 1885, as all we're ordered options. It's noted that the angle on the staff for the model 1876 is slightly different than the ones stamped 1873 and 1885 making them difficult to swap as the vertical staff wouldn't stand vertical but on an angle as the wrist angle on these Rifles we're different. I agree with your earlier comment on a different spring stamped for the 73 and fitting that Rifle. Cant imagine that would be easy to find either. These are still very hard to find as a Thick Base Winchester mfg. sight as by the early 1920's Lyman was supplying Winchester with most of their tang sight along with a few other mfg. as far as sights we're concerned. On the tag in your pics there's a tag and at the end I understand it to claim 3rd, which I assume to mean a 3rd variation but I disagree with that as the thick base was only offered for a short amount of time in a first variation. I find this pretty interesting. Thanks for sharing.
HS 58
I Learned a long time ago to Separate My Want's from My Needs!
