I haven't seen the gun in about 15 years other than in pictures, he doesn't bring it out very often. I plan on going to see it in the next few weeks. I will have a closer look for numbers then. The story has always been that my Great Grandfather got it from an Old Sea Captain.
I asked my Uncle and he doesn't think there is a serial number or a grade number, although he thinks it is one of the lower grades. It says Baker Pat on the locks. So if it has that, it must be older than thought, pre 1883?