Is this the original tube that went with the chassis? What size is the tube? The wavy stuff could be a B+ issue...
leaning towards the B+ being off. there are instances where the voltage regulator can fail and it doesn't spike the B+ enough to hit the HV shutdown.
are you using a plastic adjustment tool for the width coil? aside from the fact that using a metal hex tool will result in the tool getting extremely hot, you can damage the core that you physically turn inside it using metal. (so the legends foretell)
you also appear to have either a degauss not working (the coil around the tube not being plugged in perhaps) or a purity issue with the purity rings being out of adjustment. the left side of the screen has a purple look in the white crosshatch. a loose/moved yoke could cause this too, but that would be a more uniform effect across the screen I would think.
the tube looks healthy -- you have white, which means your colors are firing properly. you won't need a rejuvenator for this.
to test B+, there's the large ceramic resistor mounted on the side. one leg of the resistor will be the regulated voltage (on a 25" monitor it should be around 130V) and the other will be unregulated (either 160 or 170V, my brain is mush and can't remember at this moment). if you're seeing about the same voltage off both sides then your voltage regulator is probably toast.

you use the metal heatsink for the ground.