I would venture to guess that if this is a civil war era revolver it would be confederate made. Union blockades preventing the south from being able to obtain stock thick enough to produce recoil shields on their weapons. As well scavenged and surplus parts would be recycled and retrofitted to produce a working firearm by local blacksmiths and gunsmiths of the era. It is definitely not a Dance model. I have one. (See Pic) But it appears to be an attempt at a recoil shield and the stock wasn’t thick enough or perhaps it was cut to melt the steel to use for another part to conserve material.
Here's a Dance to compare with the first post, etc. It's all matching but certainly has "Seen the Elephant". They're almost impossible to find in a higher condition grade, as those are mostly locked away in museums and collections.
notice the 'twist' in the cylinder to strengthen the metal.
Actually that twist in the metal was not purposely put there to give it strength, although that is exactly what the twist does, the twist was a result of using twisted iron bar stock (Rebar) to make the cylinders out of, as that was what was available at the time due to Union Blockades. Steel was hard to obtain. When the iron bar was ground down a faint twisted line was visible. It added strength and helped to keep the cylinder from exploding under high pressure. This mark will only be found on true Confederate revolvers.