For sale is a massive antique skeleton key vintage the 1700's or 1800's.  It is nearly six-inches long (roughly 5-7/8"), about 1-5/8" at its widest point, and weighs three ounces.  I am not sure whether it is bronze, brass, or something else, but it has a beautifully aged patina.  There is a triangular stamp on each side of the bit, but the markings are obfuscated by wear and age.  These types of keys, especially these huge ones, are becoming quite scarce as collectors snap them up.  It is in very nice antique condition.  This key was obviously kept inside and not exposed to the elements.  Please refer to the photographs to gauge condition.