Andy45: I don't know about the sights, except they are the original issue. The jeweling you see on the hammer was done by the gunsmith I bought the gun from in 1963. He also smoothed the action. Since then I have replaced the springs with Wolff (have several return spring weights depending upon the ammo to be used). Because of its very light, smooth trigger, it is easily the most accurate gun I own. Sorry to say that it looks so new because I don't shoot it as much as I should. Thanks for your comment.
These early (Pre-Series 70/Mark IV) Gold Cups are becoming valuable if original. I suggest acquisition of a correct hammer and magazine before they become more difficult to find. Using the correct grit of sandpaper, it might be possible to remove the engine turning on the hammer sides by putting the paper on plate glass and carefully drawing the hammer sides across the paper in the correct direction, but it is hard to duplicate the factory finish. If memory serves, the round axle area of the hammer remained blue, which will not be possible with the sandpaper method suggested, but at least that would not show when the gun is assembled.
The Elliason sight was not used on the first Gold Cup series. The rear sight should be an ACCRO.