1930s vintage package spiral pin fasteners for chair sets, lace doily tidies for chair backs

Unused package of Kant Slip Spiral Tidy Fasteners for chair set doilies (wouldn't want your antimacassars to become mussed!). The paper card is a little worn and grubby, but has the sweetest graphics. There's thirteen pins here, so I think a spare pin was included, or added from another set.