Your rifle was built around September of 1881.
If in original condition, it should still be equipped with the Model 1879 rear sight - marked with an 'R' indicating 'Rifle' - but if it was upgraded, it may well have a Buffington rear sight - the earlier one looks like a ski jump - the latter is 'flat'.
Anything more will require good, clear photos - taken in natural light - so if it looks like a marking on the wood - take a photo of it.
These were surplussed out decades before it was sold out of that courthouse - sold by the NRA, the DCM, even Sears, Roebuck & Co.
Unless there happens to be an actual unit marking on the buttstock, it'll be close to impossible to say where it served after it was built.
Scouts Out!