We were fortunate to see a lot of ledger entries while working on the Model 1895 book.  There are notations for tang sights having been installed at the factory, but not very often.  The Marble Special Base sights are one example that was used.  Like Clarence says, the Lyman receiver sights were almost always used when a rear aperture sight was installed.  Lyman patent text and advertising for the Lyman No. 21 mentions the long bolt travel of rifles like the ’95.

I have noticed tang sights on ’95s in old photos more often than I’ve expected and would have to guess that many of those were put on post-factory.