The technological revolution ain't what it used to be, no sir. Time was, you didn't know what a part was and installed it wrong, an industrial machine could macerate your hand, rip out your hair, suck your cravat in right up to your sideburns. You put the wrong part on, why, could lose a nose, an eye, an arm. Yessir, you wouldn't want to dally 'round gettin' your fingers greasy without readin' the manual first, making sure you knew where everything went, and what it did, and what would happen if it broke. Not like nowadays, where it's all code and passwords and glowing words that hurt your eyes, and it's guesswork and you can never tell if the people sendin' ya letters about your house or your apothecary order or the size of your tallywhacker is even men or women. You never have to get your hands dirty, or even move, much. It's all guesswork and hoodoo and a buncha black magic, I tell ya, and I don't pretend to understand none of it.
But this here little gizmo, I know this has gotta be for some kinda big sewing machine, right? It's cast steel, with a v-shaped channel cut into it big enough for thread, and some sort of eyelet whatsis screwed into it. And there's a sharp end, and a blunt end. Oughta be able to figger it out, oughtn't I? Right? Say, what'n hell is this doohickey, anyways?