Well I got around to building one of these, picture below. I have not been able to get the red leds to flicker yet, but I am using a Z-1000 brick for testing, and I am thinking it may have a built in TVS, thus limiting spikes. I'll have to see if I can scare up a conventional transformer, like a 1033 or similar, and see how that fares.
Note I used 5 mm leds, only because I have lots lying around. But you could just as easily use 3 mm ones. This build is for portable use so I connected wires with small alligator clips. The plan is to build another one for permanent mounting in a suitable rail car, as discussed in the opening post.
Thank you Stan for sharing the original circuit with us!
Rod
