Epilogue...
I was going to post the numerous ways I've used these circuits since I first set up this thread but felt it unnecessary as most can pretty much figure out their own uses with a little imagination and inginuity. However, the original device, while a crowd pleaser at shows, wasn't satisfying as a model, looking too much like an LED tacked onto a model freight car. Since that time, I've modified it slightly to look much more like a true FRED ---and--- it was relatively easy to do.
I bought an LED assortment from Radio Sham for $3. In it were several large red LEDs. Using a bench grinder, I squared up and reduced the LED's size, taking care not to remove any material around the element. It is much easier than it sounds, the red plastic falls away like glass leaving no burring of any kind.
I then cut a piece of shim brass for the face, drilling a 3/64" hole centered at the brightest point on the LED when lit.