Good job. In your schematic you marked DL1 as BZX84-C8V2 which is a 8.2V zener diode. I also checked the schematic made by @jonschultz which marked DL1 as BZX84-B36, a 36V zener diode. Which one did you use to get it working?
Also seems XC1186B does have xray protection, DL3 is fed by a sensing winding in flyback transformer, if HV is too high (higher than zener voltage of DL1), pin 30 will be pulled high and trigger xray protection. Never noticed this circuit before, and don't think it's causing issue with 84V VGA mod. What's your voltage reading on TP27 and TP37 when it's powered on by the way?
Also regarding the hourglass distortion and horizontal width, if you can't stretch the image wide enough, try to add a high voltage capacitor at CL26 right next to HOT. I can increase horizontal width to fill the whole tube without hourglass distortion in the middle by adding a HV capacitor around 3.3-4.7nf. You can also increase +B a little bit to get more horizontal width but it also changes geometry settings.
Good luck.
Also seems XC1186B does have xray protection, DL3 is fed by a sensing winding in flyback transformer, if HV is too high (higher than zener voltage of DL1), pin 30 will be pulled high and trigger xray protection. Never noticed this circuit before, and don't think it's causing issue with 84V VGA mod. What's your voltage reading on TP27 and TP37 when it's powered on by the way?
Also regarding the hourglass distortion and horizontal width, if you can't stretch the image wide enough, try to add a high voltage capacitor at CL26 right next to HOT. I can increase horizontal width to fill the whole tube without hourglass distortion in the middle by adding a HV capacitor around 3.3-4.7nf. You can also increase +B a little bit to get more horizontal width but it also changes geometry settings.
Good luck.