No chroma board should only have color osc, demod's stuff like that, not B+ Boost
stuff on it....
If you feel that you can handle the efficiency coil adjustment I think you should at least
set up for it, and see if there is a working adjustment there.... Like some range, and
keeping under the current they recommend.....
Be very careful with the coils, you don't wanna do any damage with that stuff, It'll
be on the brittle side....
You may want to look at measuring the B+ Boost with that HV probe....
This has it marked, you can see it on the schematic near the 6BK4 tube.
They don't give a number. Sams might say something about B+ Boost,
check it out.... You can see how the B+ Boost goes right over to the pin 3's
of the screen adjust pots.... Your voltages look 100V too high, even at
cutoff.... I wonder what they would be if turned up a little.....
http://www.boxcarcabin.com/rca-ctc11-schematic.gif
If you can determine if the Boost is too high, then it's a matter of
testing each component to see if you can find it....
Is that focus rectifier good...? You said some resistor near the focus coil
was burnt up, was it R109 - 100K...?
Also you replaced the flyback with a Thordason same as was in it when you
got it, you have to begin thinking that two pins may be switched... You
may need to see how to check to be sure that that transformer was the
right way to begin with.....
.