Need info on 1949-50 instrument cluster ?

[big job]

There has been a lot said about these with little or no lighting. I have not
yet found what is actually in there. I have all new #55 bulbs. The only
bright ones are the directional arrows. I have read about some kind of
black film around the bulbs that react with (don't know) 'iridium or phosphorus or something' ?? not a case of painting bulbs green, something is blocking the
light. And then I had a Westclock alarm that looked like this cluster. It glowed
all night in the dark then began to fade, then I use to shine bright flash light
on it and gave it a recharge and it glowed again. So I shine up the cluster
and it did have a slight glow. My reason for this was I was issued a company
car a 1949 with over drive and that dash lit up like a 747 even the clock glowed, but that was in the sixtys. So now at 70yrs guess it has a life span.
Then remembering the night clubs with black lighting man the place lit up
like fire..... so someone here may have taken one apart. sam