'10bears' - A logical route to go, for a facsimile of a carbine, is to simply to use a Krag model 1896 rifle rear-sight. The rifle sight dimensions are the same as the carbine sight. The significant difference is the spacing and magnitude of the range graduations.

S&S Firearms offered (and maybe still offers) a reproduction carbine rear-sight that was actually a 'remanufactured' rifle leaf and slide. Photos of such a sight are shown on the KCA photo page. (It's pretty crude, ugly and a waste of effort).

IMHO - It is better to use an honest model 1896 rifle sight and not mutilate an original part. Such a sight can often be found for $35 to $45.

---