Does anyone know the correct finish for the Autolite brass temperature sender and how to achieve it? I've got a couple of good used Autolite senders and they need cleaned up. Tried to buff one but the finish looks "too good" if you know what I mean. And also on the sender, the insulating material at the top, is it supposed to be a nice clean white or is it sorta off-white. Thanks for any and all help!!