I'm rolling with laughter, girls! The object on the lower right has nothing to do with sewing. We should run a contest to identify it.
Aw shucks, I'll tell. It is a cable clamp from the inside of an electrical box; the type of box you have in your walls that hold your electrical outlets. It holds the electrical cable from pulling out of the box and puts that pulling strain on the box not the outlet. This would be from a fairly old box because they haven't used that type in years. Wait, maybe they still sell 'em.