Thanks to a member here, I procured a replacement VFD glass. It works now!

The problem seems to be the capacitor mod to fix the glitchy dimming. I put on a 0.01 uF cap (maybe the wrong value?) and it obliterated the CS signal to the pot. This in turn cranked up the voltage to 117V which fried the VFD.

So instead of the cap I decided to fix the source of the problem and I put a 820 ohm resistor on the one-shot circuit. This is a resistor under the VFD; it used to be a 620 ohm if I recall. No more dimmer problems and the voltage is good now. This empeg will live on!