Success. I used a bit more solder than was likely needed, but the clean-up wasn't too bad. Wonderful ringing tubes now.

https://drive.google.com/open?id=1K1YKmjTt9QtmXswX_jMluZQH2ceHmsRi

https://drive.google.com/open?id=1LkjG-8YYlpoZQvcxhJIwzUgD40NJTESp