Hello TAC001,
Your revolver was shipped in July 1863. There are three inspector cartouches containing the letter G identified in Remington Army and Navy Revolvers 1861-1888. CGC for C.G. Curtis, GP for Giles Porter and GRC for an inspector who has not been identified. It is not uncommon to see a portion or all of the cartouche worn away on revolvers showing heavy use. Are there any other letters stamped on the major parts of your revolver frame, barrel, cylinder or trigger guard? If so these would indicate a martially inspected revolver.
Hope this helps,
Bill