I did a bit more tinkering with it this evening, and what I ended up doing was covering the tops of the lights with some card stock. This blocks some of the light from coming through the top, and kind of mutes the light inside the cabin just a tiny bit.
What it really does, though, is makes it so that they aren't so pronounced inside the cabin. The way I had them before, the top of the lights was by far the brightest part, and it kind of drew your attention directly to them when looking. Now they are a bit less noticeable, while still providing pretty much the same overall look.
I was a bit conflicted about the flickering lights, as the boat clearly has electronics (radar, spot light, things like that) but I also think it gives it a bit of a cool trait. If someone wants to argue that the boat would never have had lanterns in it, I'll just tell them she's got some electrical gremlins!!!