[DMcMahon]

Thank you Chris for your excellent analysis in the above 2 posts, all clear and makes a lot of sense. Later today when I check out the various voltages, I will more closely look at this.

I can now see the +220 & +160 volt supplies at the X timebase module.

My documentation does not have the "Reserved for Solartron Development" annotation,
pins 1 and 2 of SKC are the X timebase drive signals to the CRT X plates.

My new replacement for R304 (18k) was a carbon film 0.5W, of course being modern it is no larger physically than the original old failed 1/4 watt.

Plenty of spares came with the unit:-

2 x CX 1443 X timebase amplifier plug in modules (one with 3 valves missing).
1 x CX 1441 Y timebase amplifier plug in module.
1 x CX 1442 H high gain differential amplifier timebase plug in module (1 valve missing).
1 x CX 2841 Y timebase amplifier plug in module (this is solid state, so assume at this stage that not a compatible plug in for the CD 1400.

David