Vintage Ornate Cast Metal Dagger (letter opener) and Sheath -Made in Italy

Very ornate cast-metal dagger-shaped letter opener and sheath, 7 1/8" long. When in the sheath it all measures 8 1/2" long. (Metal unknown: too heavy for aluminum, but not iron--not magnetic.  Silvered pewter??)  Design looks sort of European/Gothic to me. (Any info as to origin gratefully received!) Very good condition.