Dax, The PL Enterprise kit isn't like the old AMT/ERTL ones. I know the guy that made the master molds for the kit and he made it so that you can glue it togather with model glue and not worry about the nacelles or the saucer section dropping or snapping off. but if ya want to put a brass rod in there, ya would still have plenty of room for lights in the neck if you wanted to light the model. Another idea ya might want to do is after you glue the bottom saucer to the neck, melt the tabs that stick through the holes so that they would not fit through the holes anymore.
I glued a test one togather and the saucer stayed glued to the neck even after falling off my desk onto the floor.
Melting the tabs sounds like a great idea. Thanks!

Would I be correct in that your friend is the guy who runs the Thomas modelling forum? I signed up there a few days ago, but it seems pretty quiet. He's also the guy behind PNT models and custom decal graphics?
From what I have found it looks like I'll be buying a 556 timer for the nav and strobes, but I'm wondering about the size of the LEDs. The amt 1/537 special edition uses 3mm LEDs which are way out of scale and I note the supplied opening in the polar lights 1/350 is about 1mm. I have found some 2mm LEDs online, but they are not dome shaped. At least on the 1/350, 3mm won't look so badly out of scale, but the red ring / circle decals for around the nav lights won't be useable.