The ABL runs off the reference pin of the tripler IIRC. Its the pin
with the big resistor & is just above ground to produce a small voltage
that varies with beam current.
With a good CRT as a rule G2 pots start to show a line at abt 1/3.
You need good boost IIRC between 800 & 1000 VDC. If thats OK
look back to to the G1 & K's. A bad boost filter will lower the boost
& leave unwanted crap on it.
I really suspect the tripler. Its the common link between the sets.
There are resistors, caps & diode stacks in them that may vary in
value from the OEM tripler.
enuf fer now, time for a beer. Or 2 or3............
73 Zeno
LFOD !