Singer 301A repair/ replacement parts.  Rotating hook assembly #170158, consisting of: rotating hook #170135 with two set screws #462AL, rotating hook gib screw #140694, rotating hook loop guard #170128, rotating hook gib #170160, bobbin case base #170166, loop guard screw #200145c and gib hinge screw #200164c.  Price includes shipping to lower 48, return for refund if fails on your machine.