.
You can check this list every few months,
https://docs.google.com/spreadsheets...18&single=true
It belongs to the vintage television museum
https://www.earlytelevision.org/
You will also have to ask G about substitutions for your original. I think you
can get a substitution book at the museum's website look under resources
old books - they have a few....
Check this book pg 91 & up.
https://www.worldradiohistory.com/BO...ume-4-1962.pdf
And this one.
https://www.earlytelevision.org/pdf/rca_hb3_pic.pdf
You might have to pick one that is close physically -
Or you can wait for another similar tv to come along
and buy it and hope it's got a better tube....
As for your old original, you can try a brightner
you'll have to figure out which one to get and
they are on ebay for $20. or so....
We all have sets waiting
on a stronger tube...
Good Luck!
.