The Arms & Equipment in the Civil War Message Board

Sharps New Model 1859 Infantry Rifle

I have recently come into the possession of a New Model Sharps Infantry rifle with serial number 59152, placing it in the last part of the New Model 1859 issue. The rifle is in pristine condition but has some interesting quirks.. Maybe someone on this board will have some ideas.

Gun is standard .52 caliber, 3 band made for socket bayonet. It has standard cartouches (3) on wood etc.. but... it also has a post war banner cartouche on the "off" lock side of the gun about where the cheek rests. The barrel is also marked "Sharps Rifle Co. Bridgeport Conn. " in a single line between the 2nd and 3rd barrel band..instead of the Hartford address ?? I have not had the barrel off but assume the barrel serial does not match the reciever.

I have heard some guns were assembled out of spare parts after the war but why would this have been done as reliable self contained cartridge arms were making percussion arms a thing of the past ??

Anyone know?
Thanks in advance for any feedback