lAccording to the data sheet for the D5-100, the deflection sensitivity is about 100volts per centimeter when operating at 2000 volts. I believe that the hv in the Pilot is closer to 2500 volts, which would reduce the deflection sensitivity to around 125volts per centimeter.
http://www.r-type.org/pdfs/d5-100gh.pdf
The vertical height of the D5 is about 3 centimeters, so it would require about 375 volts to scan from top to bottom of the screen.
The voltage that you have available from your B+ and B- supplies, which power the vertical circuit is less than 300 volts total, so you can’t achieve a full vertical scan.
jr