I did something similar, with the power socket placed close to the keel on the bottom of the hull, but ran the cord from the socket down through a hole in the display case and ran it to an A/C receptacle outlet for power instead of relying on batteries. Using a battery box has the advantage of making the entire model more portable. You may be able come up with a way of hiding that battery box in your model display so it isn't visible. One could make a box of stained wood to contain the battery box and disguise it as part of the model's mounting cradles. Or, hide it in plain site buy turning such a box into a mount for a ship's nameplate. Only the wires running to the hull would indicate that the nameplate is holding the batteries. Just brainstorming here. . .
