I do remember using lace tightening hooks for skates much larger. What looks like a rock i think is slag formed from intense heat. When I first found one I thought it was a meteor, and soon found hundreds more.Similar tools were used for tightening skate laces but yeah, probably button hook. What's tha lower left first pic? Nice bottles by the way.
The bottle was made sometime before 1900 since it has a key mold base.The lip is called a double bead lip.See if the seam stops before the lip.I can't tell for sure if it does by the picture,but all pre-made machine bottles the seam stops somewhere on the neck or up to the lip.