That appears to be a Leece Naville alternator, and it might have been installed by Cadillac, however, the hole in the core support would have been there when the core support was manufactured. Compare the alternator with the one on the Pinner ambulance, because they are both the same vintage, so they should be alike.
The white switch is a Cole Hersee switch, and it has 2 or 3 pull out positions. Full in = off, first out = parking lights if it were used on a truck, so it might have been to activat the "running" lights, and second out, would have been headlamps, or in this case, the emergency beacon. If there is a third position, this was used for the high beams. The 3 position switch is quite rare to find today, because they were not common in the day of manufacture. I have a NOS 2 position switches, if you should need one.
The white switch is a Cole Hersee switch, and it has 2 or 3 pull out positions. Full in = off, first out = parking lights if it were used on a truck, so it might have been to activat the "running" lights, and second out, would have been headlamps, or in this case, the emergency beacon. If there is a third position, this was used for the high beams. The 3 position switch is quite rare to find today, because they were not common in the day of manufacture. I have a NOS 2 position switches, if you should need one.