Don't know if it's too late or not here, but this thought just occurred to me, plus I'm hoping for an update to I can try to duplicate your work or commission you to do my CR90 and Raider.
The Homeworld Remastered Collector's Edition had a ship model that was lit up, and it was powered by a USB cord that plugged into the base and ran up through the (relatively) thin stand into the ship itself. Maybe you can use a rechargeable battery with a micro USB port on the ship? Knowing nothing about electronics except how to use the ones other people build, I have no idea if I'm spouting nonsense or not, but hopefully I'm not.