The carbine pictured by Meta is a Model 1860, made in early June, 1864.* It was later one of about 12,000 which was refurbished between 1866 and 1874 by Springfield Armory and had the Stabler cutoff added.
In the refinishing process, the original markings were often polished partly away, which accounts for the partially obliterated marking on that one. The metal was re-case hardened and reblued as appropriate, which explains the slight pitting under the new finish seen on yours.
The original .52 caliber, 6-groove 22" barrel chambered for the .56-56 Spencer was drilled out and sleeved to a 3-groove .50 caliber, chambered for the .56-50 Spencer, the same cartridge used for the new 1865 Model.
The stocks and foreends were sanded, obliterating the original inspection cartouche (ESA), and a new cartouche stamped on.
There were several of these, but yours is TJS, the mark of Thomas J. Shepard, an Armory Sub-Inspector.
I would put a guesstimate of value in that condition at around $2900, retail. Regardless of value, the gun has a lot of history behind it.
Incidentally, the rear sight leaf is turned backward; it should fold to the front.
*On June 9, 1864, W.A. Thornton, Inspector of Arms, reported finding minor flaws in two Spencer carbines, 29752 and 29792, the latter only 48 away from 29840, which would have been produced close to the same time.
To give credit where due, the bulk of this information comes from Spencer Repeating Firearms by Roy M. Marcot.
Jim