I have a confession to make and I'm not proud of it (

), but the reason I know its brass is because I used a chemical to pickle its color black to match the rest of the sword. The brass was old and yellowed with age when I got it, but contrasted so smartly with the rest of the dark sword and looked like a wad of gum holding the blade in place, so...I altered it to look more appealing. No trickery on my part, just wanted to have a less ugly appearance. So the surface of the brass now looks "off". Unfortunately, I don't know what to do about returning it to its former state. I'm afraid I'll wash away the patina and then it really will look like a "put-together" sword, which I truly don't believe it is.
Does anyone have a suggestion of what I might do to remove the pickling to the brass??