Today, I decided to refit the CRT and wire up the scanning coils. Plenty EHT and the tube is displaying a bright thin horizontal line, at least there's some video activity in the line proving that the video amplifier is working.
Operated the system switch while the set was working, bad move, killed the line output transistor. It's a 2SB275, PNP germanium type.
https://www.radiomuseum.org/tubes/tube_2sb275.html
An AU113 will serve as a replacement.
DFWB.