Vintage Missouri State 3D Metal Brass Ashtray

Missouri State shaped 3D metal brass? ashtray. Measures approx. 6" x 4 1/2" and depicts horse, pony express rider?, donkey, cow, soldiers, fisherman, deer, boat , capital +. There is a leather pad on the bottom to keep it from scratching furniture. I'm saying it could be brass since it has a few spots of green patina on it. Very cute piece.