The commercial New Service revolvers were finished in the polished Colt blue of the period. Look carefully at the edges of the markings, use magnification if necessary. Colt parts were polished BEFORE the rollstampings were applied so there should be visible raised edges to the stampings. Usually most obvious in the Rampant Colt - they lose the hooves and the arrows with almost any polishing.
The autonomic nervous system provides for involuntary muscle function - the work of breathing, digestion, and so forth. On some folks, that's a pure waste of ingenuity.