65 Dart Alternator Not Charging
Looks like I won't be testing anything tonight, the brush on the outside just fell apart. It was looking pretty fragile, guess it got bumped and the whole part is gone now.

The exposed one popped off.
I have the single field terminal alternator, but it had both of these brushes on it. I'm confused about the function of the one that was outside the alternator. The above picture is the way the terminals were mounted in the alternator. Is the exterior one just a spare?
Since this is the single field terminal, there isn't an "insulated" one, since this is ultimately connected to the ground terminal which is grounded to the case, correct?