How to wire up 1940 rubber CMP tail lights

[Lynn Eades]

Hi Rob, these are the lights.
The insulator part appears to be permanent in the brass (nickel) body.
It looks like the only way to hook the wire in is to solder it in, but as the ends actually contact the sprung pins in the light body, it seems wrong to me.
I have wondered if there was a crimp or soldered termination, but the holes are too small to allow it.
I have another type that the insulator drops out of an alloy body, giving access to screws that clamp the wire. I would however like to use the originals.