Tom,
One is marked “Light”, the other “IGN”. I assume it is for some sort of remote shut off, and to power some other light, maybe navigation light? Really never seen anything like this. This is the “salt water” edition with lots of bronze, so maybe it was a sailboat thing?
I found a replacement mag plate on FleaBay, so I will wait to take the mag apart to be sure things are the same.
David Bartlett
Pine Tree Boating Club Chapter
"I don't fully understand everything I know!"