Woody,
The folks back in those days were minimalists. I actually think there is a fuse, or if not a fuse, then a thermal overload on the headlight switch that covers the headlights.
I don't know if this headlight protection covers all the dash lights and dome light, but if you think about it, there isn't much more on these old hogs to protect...and you're working on yours, so it hasn't burnt to the ground yet.
A dealer installed radio was probably equipped with a inline fuse, as would have been a spotlight or lighted cigarette lighter. It seems prehistoric, but I don't think it's as scary as it looks.
Stuart
