The photo shows my steps for aging the fittings, and making them a little less recognizable as a part you probably have under your kitchen sink. The top piece is in its originals state. Going around clockwise, I sanded off the sharp edges; I sandblasted it to remove any lacquer; and I buffed it. On the far left bottom I've dipped it into vinegar a couple of times which brings out the cuperate patina. And above it I dipped it into Liver of Sulphur which turns the copper in the brass brown.
I will age all eleven of the fittings together to hopefully a nice dark brown.