We have a Cast Iron Shoe Form Vintage Item.  It has the number 4 on the mid portion.  About 1/2 of the original finish is still on this piece with the balance being a light rust.  It measures about 9 1/2" from heel to toe x about 3 1/2" across the widest point x 2 3/8" in H.  There is an opening on top of the ankle which is about 1 3/4" one way and 7/8" across the center cross x 1 1/2" in depth.

Shoe Form Cast Iron Vintage Item