I would leave it alone unless your are prepared to restore the whole rifle. Bright Colour looks out of place on a worn rifle. Case Colouring also requires dissasembly and heat, both can damage your rifle if not done properly.
A little honest wear and character never hurt any rifle and it is almost a 100 years old.
-------------------- Lovu Zdar
Mick
A Man of Pleasure, Enterprise, Wit and Spirit Rare Books, Big Game Hunting, English Rifles, Fishing, Explosives, Chauvinism, Insensitivity, Public Drunkenness and Sloth, Champion of Lost and Unpopular Causes.