Thanks for the link Forbin.
My dad bought and built me the Long Box version #2 kit (Kit # S951-250), I was too young to build it. It must have been either the Spring of 1970 or 1971. It took 2 "C" or "D" size batteries in the secondary hull to power the 4 lights; 1 light for the green clear bridge dome and 1 for the green clear lower dome on the primary hull and 1 light behind each of the orange translucent nacelle caps/domes. You turned on the lights by turning the cylindrical Sensor Dish Mount, located at the front of the secondary hull which had the antenna dish sticking out of it, clockwise.
When I got the Enterprise and the Klingon battlecruiser kits in 1975 for Christmas, the Enterprise no longer had the lights, but it was still fun to build them both on my own.
Navigator NCC-2120 USS Entente
Edit: The culttvman article above states that the model kit took 2 AA batteries but I have always remembered them as being either 2 "C" or "D" size batteries. Maybe my memory is faulty, anyone else remember what size batteries their kit used?
Stokely: In an insane society, the sane man must appear insane.
Harvey Holroyd: Where'd you get that?
Stokely: Star Trek. [leaves the room]
Harvey Holroyd: [to himself] God, I miss that show. (Source: "Serial", 1980.