Even at that large scale, individual LEDs would be impractical. Your fiber-optic approach makes sense,
On the down side, fiber optics don't put out that much light and the switch labels would be difficult to see in "normal" (daylight) conditions.
Another resort would be using plexiglas and edge lighting. If you get a 1/8" piece of clear plexi, scratch a surface, then shine a light on the edge, the scratch shows up. This is how the gridlines were displayed on the old CRT-based oscilloscopes etc. Once again, the illumination is not very bright.