Old Antique Percussion Type Possibly Civil War Pistol Gun

Handle grip is worn (wood smoother than the rest of the gun), a plate on both sides, no markings (as often the case w/the kentucky pistol but I'm not sure if they had markings when changed to percussion after 1800). There's considerable red markings along the crevices. I removed the one plate in order to look under it and there was black hardened stuff under it that could be scraped away. The cock is pulled back 2 x with 2 clicks. The barrel extends 1.5 inches beyond the wood part of the run. The ram rod is missing. There is an impression on either side of the wood part of the gun under the barrel where there was probably a bracket at one time. This is missing. The screw posterior to the trigger has been replaced by a newer screw. I used an unraveled larger paper clip to determine the length of the ram rod hole and it was approximately 6 inches. There are stripes inside the barrel each measures 1/8 inch wide. Looks down the barrel, the stripes appear to extend. Barrel is octagonal. O.D. of barrel is 7/8", I.D. 1/2".

Note: I would like to sell this, but I want to find out it's value first.