LEDs may be hard to fit in there. The distance between the lens of the light and the housing is only like a 10th of an inch, which is what makes them flush to the body and why they used the paper in the first place. Also, the paper produces a very pleasing light that does not violate any state codes. It is very soft, soothing, and evenly spread light.
On the other hand, LEDs produce a rather harsh and bright light. They can be dimmed but it is unlikly that you will get as even of a light pattern as what you get with the paper. Here are pictures of both my '88 and my '90. Unfortunately the inverter on my '88 took a dump at the end of last year so if anybody can get me a working one I would pay you handsomely.