Antique Pair of Steel Cut Shoe Clips or outlet Buckles

Pair of antique, faceted, cut steels shoe clips or buckles circa 1920/30. These buckles are outlet curved, not flat and measure 2 1/4 inches wide by 1 3/4 inches high. The steels are clean and very fine. One buckle is missing one steel, thought I saw another but now I can't find it. No breaks in the metal.

The Evergrip clips can be removed. They have a patent number no. 1728763 F.B.N. Co. This patent dates to 1928. Behind the clips are pieces of faux leather, meant to protect the vamps from damage.
Gray sparkling beauties.