Unfortunately, I cannot see it at work as ebay is blocked, but this is the exact reason the 2E5 magic eye tube exists.
It was made to retrofit early 30s radios with 2.5V tubes and AVC.
It was never used in a production radio.
Granted, how well the installation is done changes things.
I have a GE J107 and a Stromberg Carlson 51 with a 2E5 installed.
I've considered returning the Stromberg Carlson back to its original state as I do have the correct tuning meter to install, but should I?
I'm on the fence.

Thoughts?
-Steve