Aww. What's wrong with Nixie tubes? I thought I saw, long ago, a free nixie tube model. Or you could do an old seven-segment (or the more modern 15-seg) and activate a glow channel on a number-by-number basis. The trick would be to use the "Discrete" tweener so nothing changes for most of the second, then a bezier tweener over a quarter-second or less to turn several segments off and others on. The cute thing with this is that you could add a single blinking segment or four in rotation as some stop-watches do to show fractions of a second spinning past.