Before sewing machines had round bobbins, they had a long, skinny bobbin that was housed in a shuttle, such as these. The one on the top is from a Singer 128, the abused one I’ve been fussing with. It will never sew again, likely. Interestingly, the shuttles were something that was periodically replaced by the machine owner. The new, never used one pictured closest to the ruler is one of these. Sold in the same shops that sold needles, the housewife would pick up a new shuttle when she noticed skipped stitches or other problems. It’s as though we could pick up a new bobbin race and assembly at the fabric store. I think it is one of the reasons that these machines can last for 100 years and still be used.
So, why do I have a shuttle without knowing what machine it belongs to? Well, because it was inexpensive, and seemed worth a shot that it might fit one of my machines, or a machine I will someday get, and because its shiny!