Very nice and unusual set, featuring 3 different size cast skeleton style keys, similar to old cell door keys, on ring with a spring loaded medallion clamped over the "break" in ring.   Medallion appears to be bronze, and has a maker's mark inside (pic included).  The medallion has a very detailed relief on each side of it.  Very good and condition.  Moderate patina that I made no attempt to clean or polish.  Please see pics for further description and condition.