from the pics the discoloration is patina or a polite form of rust. patina is what happens from age when a firearm isnt regularly oiled and the oil dries up. over time the finish, which is bluing a form of rust, turns brown. you can distinguish patina from actual rusting metal is an acceptable patina doesnt have pits and is brownish instead of reddish.
the bluer it is and the fewer pits the more valuable the closer it is to original blueing color the better it was taken care of. patina only has a zero negative is when there are no preserved blued models left.
however if you try to remove patina it ruins the value as that takes it to bare metal and little value. while patina isnt always good its not all bad. removing it is always bad
"Gun control: The theory that a woman found dead in an alley, raped and strangled with her panty hose, is somehow morally superior to a woman explaining to police how her attacker got that fatal bullet wound." — L. Neil Smith
The problem with being stupid is you cannot simply decide to stop doing dumb things...
"I crapped my pants to avoid the draft!!" -Ted Nugent
Last edited by JonM; 12-06-2013 at 06:03 AM.