This is an LR 94 Index 10 [F] HICKOCK'S PATENT [R] 1859 in Dark Teal. It is 3/8" taller than usual, according to Steve Bobb's Lightening Rod Insulators Catalog, (see here: https://www.insulators.info/books/catalog-of-lightning-rod-insulators.htm). The embossing is weak but readable, and there's slight roughness around the sharp edges. It'd be hard to upgrade. Asking $200 shipped in the U.S. CK/MO.