Taz is correct, as usual. Note that your hook has a sharp point ...which the sword-scabbard-hanger hook does not have. Your find is a curb-chain hook from a horsebit, as shown in Taz's photo. To see it specifically documented as a curb chain hook, look at the lower left corner of the photo below, which shows a page from the 1907 Pierson-&-Howe mailorder catalog of horsegear. (You may need to use TreasureNet's super-enlargement option to read the word "Curb" next to the sharp-pointed hook in the catalog.) Let me give public credit to Creskol for originally posting the photo here at TN, a few years ago.