• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

VFD tube short

I know absolutely nothing about those model of tubes, but here is a little bit of common sense reasoning:

If the tube is shorted and is not working . . .

Pass enough current between the two shorted elements; and try and open up the short.
What is the worse that can happen? . . . Smoke, fire, sparks, and the tube is still broken.
What is the best that can happen? . . . now the tube works.

Nothing to loose if you try and fix it, Right?

Just my opinion