Vintage Sewing Machine Stitch Cams Top Hat Discs Fashion Accessories

Vintage Set Sewing Machine Stitch Cams Black Top Hat Shape fashion Discs - Normal wear. Great shape. Please see photos for a more detail. Perfect addition to any sewing notion collection. Possibly used with Singer, Sears, Elna, Montgomery Ward, zigzag, zig zag, Supernova, Kenmore? If anyone can identify these, please let me know.