This clock project was fun, but quickly exposed a fundamental flaw in the design.  Incandescent bulbs simply have terrible life when constantly flashing on and off.  (Now I know why lamp test used to be a big thing!)  Eventually my stock of replacements was depleted.

Fast forward nearly 9 years and I was looking at why a LED bulb had failed.  All the LEDs in it fell off the circuit board.  Apparently they were glued on not soldered?  But the LEDs still worked. 

Looking at the LEDs I realized they would be the perfect sized and light color and output for an incandescent replacement.

I did have to modify my circuit to include a LED ballast resistor, but since only one element is on at any time, I only needed one. 

If you'd like to learn more about this display, they can be seen here:

IEE 10000-1819-B Projection Display