Bright red cathode filament wires may be a bad sign. They should be fairly dim.

Based on your description, you've got some sort of intermittent break and/or intermittent shortout that is alleviated by changing the amount of flex or pressure on the display board. That's going to take some work to locate...

I don't think a solution is going to appear for the half-vfd, unless by "solution" you mean "new VFD from Noritake".