Vintage Brass picture frames

Not 100% certain they are brass as they do not have any markings or stickers. Black velvet backing, able to stand or hang on the wall. Two toned frame is 4 3/4 inches wide by 6 1/4 inches tall. Large Curved Corner frame is 6 x 8 inches Smaller curved corner frame is 5 1/2 x 7 1/2 inches.