My book says 1885. Looks like maybe it's been "cleaned up" a bit,
but still a good lookin' SAA. I would definitely pay the money for a factory
letter on it. If all the serial numbers match and it hasn't been altered, you might be surprised at the value.
Can you send a cross section photo as well. You can date a Colt to at least the late 19th century by the screw used to release the cylinder pin. On modern Colts and modern knock offs the release screw is a two sided screw that you push from left to right. You then pull the pin out to release the cylinder. You have the old style that requires a small screwdriver to loosen a small screw to release the pin.
Contact Colt and get whatever paperwork you can. It may turn out to be quite valuable.
The screw you refer to is very clear in Pics 4,5,6. This is a Black Powder frame we know this by the date and Ser.# This is a First Gen Colt. I am interested in the orginal Denver Dbl. Loop holster. These holsters are correct to the pre and early post Frontier west . The Frontier was closed in 1898. These holsters are valuable on their own. Does the holster have a makers name?