Hi All I am nearing completion of a Minicraft 1/350 Titanic, which I've lit with 14 leds and over 12 metres of 0.5mm fiber optic cable and some 1.0mm cable.
All portholes (drilled out of course) and windows have been lit by removing internal decks etc, and using the bottom of the hull to throw light up from 8 warm white LEDs, using opaque plastic to diffuse the light. All windows have been made opaque using a plasticised opaque paper. I have achieved nearly the right hue of glow from within the ship - albeit it's a little too yellow - but at least there is so much light diffusion that you can't see the light sources.
The exteriors of all upper and outer decks have been lit with fiber optic cable - bunches of which are tied together and tied onto the ends of warm white LEDs. There are 80+ separate cables, and points of light, going through over 12 metres of cable. Practically all the light fittings that are in the model mouldings are now lit, and only once or twice I put in a light where there was none, just to give even lighting (forgive me). The Ken Marschall book is the reference I use to establish where exterior lights are, using his night-time images. One liberty I took was to put four 1.0mm fiber optic cables at the base of each funnel (hidden under the fidley grills for funnels 1-3) - so the funnels get a bit of light running up them (I realise the real ship didn't have this, and that's not what the fidley vents were for).
One difficult aspect about this was light masking - eg stopping light coming out where it shouldn't. I lined all deck undersides with aluminium foil, plus I used black paint and modelling filler. But this often required parts to fit together much better than they did in their original moulding - so that meant a lot of filing, fettling, and scratchbuilding.
Although my model isn't yet finished, and I haven't got an image of it's current state lit up, this ship will of course be finished for April 14th, and subsequent pictures can be uploaded before then.
I have taken photos the whole way through the process of lighting this ship, and am happy to create an illustrated tutorial which could go on this site and be peer-edited by other modellers, much like a wikipedia entry - eg - letting others improve it. Although I have tackled this task quite successfully, this is my first effort with fiber optic and perhaps a more experienced modeller could give better advice than I can.