The second version would be: Four skins, one for each glass pane, addressing lightrange and setting SPOTLIGHT via script. In both cases I would give the model an action in which the ambient or other parameters are set for a speficic skin.
lightrange, ambient and all these parameters are per entity, not per skin. So you cannot say skin1 should have an ambient of 30 and skin2 should be 10.
Don't make it too complicated.
You could:
1. Create two models, one for the glass and one for the metal part. Make the glass one BRIGHT, TRANSLUCENT and LIGHT and set its lightrange > 0. Leave the metal part as it is.
2. Just color the skin part that represents the glass brighter.
3. Create a sprite or a particle as a corona at the lanterns position and set it's BRIGHT flag.