Rare Camark Mammie and Rastus Salt and Pepper Shakers

Rare salt and pepper shakers made by Camark. Stand 4 1/2 inches in a matte blue color. Have done a little research and haven't found muchso I assume they are somewhat rare. The numbers on the bottom aren't really clear but appear to be 877 for the mold. Would like some information about them if you care to share.