The one I was going to make is shown below. All brass and stainless steel (so nothing to rust ever), a stainless ball to wipe over flat resistance wire (Kanthal wire) and a nylon piece for the wire wrap. Works like a charm, but as I mentioned can't be made and shipped for $30.
~ Jon 1952 1/2 ton with 1959 235 | T5 with 3.07 rear end