Prestolite Alternator External "Consender or Resistor"

I have Prestolite ALE 6207Y 6Z, 40 amp alternator with a Prestolite VHS 5204B-Y Regulator in a 1968 Chris Craft Lancer with a 283 cu in 185 Hp engine. I noticed there is a crack in what I think is an external capacitor/condenser/attenuator or resistor mounted on the alternator. It has no part number on it. A short wire screwed to one end goes to the B+/ARM post of the alternator and the wire to the battery is screwed to the other end. It is not the regular grounded type condenser used in most distributors. All the alternator output goes in one end and out the other. About 2 inches long and 1 inch in diameter with terminal screw on each end. Can someone tell me what this is and what it does and where can I find a replacement. Pictures attached