As I have the yellow, green, and reds, the one missing piece is the clear. I promised the actress I bought these from that I'm not going to start making reproductions. But for my own collection, I went ahead and tried my hand (pun?) at mold making. Using Oomoo 30 silicone from Amazon I made a mold of one of my reds. Turned out really well aside from the anxiety of having to wait for the stuff to fully cure up.
Next I used Art N Glow clear epoxy casing resin from Amazon. Again, easy enough - just a long wait for it to cure up. I was careful not to get any air bubbles in there. This made a really nice, clear, sharp colorless life clock copy.
Finally, I got a roll of "chrome" 3M tape from the craft store and a 5/8" circle punch for a few dollars. This made the exactly right silver backing. It is just tricky to punch the sticky tape, so I had to first apply the tape to release paper before punching it cleanly.
The final result is a pretty darn close to screen accurate clear life clock. It has that shiny silvery look - so either I'm an infant or I left the dome and found sanctuary : )
Now I've got the full set. Going to wire an LED to one of the original reds to make it blink. I've seen others make black life clocks and I know it was referenced in the movie, but I don't think black ones were actually made for the film.