Well, this might just turn out far easier than anticipated.....Famous last words. Sorry about the fuzzy pic but no tripod and a flash would wash out the lighting. Simply lightly glue a scrap of styrene on the backside of the existing dash. This will become the template for the clear plastic. I then drilled through the gauges. Remove the template and use it as the guide for the clear. Put a piece of black paper on the back of the clear for the backing once done drilling. With the black paper on the back of just the clear, I am free to draw/paint in the gauge faces accurately and can still move forward with the dash itself and detail it out without fear of messing something up. Granted a thinner "visible" dash built from scratch would look better but the cons outweigh the pros of scratchbuilding for me at this time. Anyway, once the clear and backing is done and the "visible" instrument panel is done, a bit of cement to marry the two should do just fine. I might play with putting a second LED on the lower left side somewhere to even out the lighting but space is very limited
Surely somebody has done this before. Even on 1/25 this should work. Since most semi's are flat panels, all the better. Some gentle heat will bend the clear without affecting its light carrying qualities as that how I am doing the backside of this one. That way the LED can be placed slightly away from the instrument panel to avoid any possible light bleed and aimed for maximim brightness..
Again, sorry about the fuzziness of the pix. But hopefully you get the idea..