Huvius, Thanks for the info, I will probably need some help once I collect all the necessary components. I have contacted Mark Crudgington at Gibbs, he was very accommodating and provided great information. He said " it is the 41st Gibbs Farquhasson made, it is of the earliest type and conforms to most of the original patent drawings, it would have been built circa 1873-74" He went on to say that if it is stamped 47 or 48 by the barrel proof marks it will be .461 Gibbs #1. It is stamped 48.
The barrel is 25 1/4 inches long and it has two express style rear sights, front one is fixed and marked 100 the second is flip up marked 200.
