Excellent.
The 22 inch barrel shows it is a model 1860 Spencer, and the rear sight and hammer are Model 1860 parts. The loading tube's grooves are a later model feature, but these tubes interchanged. The slight bevels on the top center of the frame (the edges of the slot where the action pivots into) were made when this was refurbished after the Civil War for post-war cavalry use, and the loading tube might have been switched at that time, too.