Now that I
don;t know. I doubt the previous owner did anything, but I
 don't know about before that. Equally, I don't know if these 3
 resistors were ever the right values, it's possible they failed in
 service and nothing was adjusted (in which case the adjustments will
 be very nearly correct if I put good resistors in), or if the board
 was twraked when the user complained about poor colour performance or
 something. Or maybe the board as originally set up for the
 incorrect-value resistors that are now there.
 Equally, I don;t know if the CRT has lost emission over time, it may well
 be that I could safely turn things up a bit.  
 Fond though I am of spending my pocket money on expensive new toys, I'd
 trust the Mk. 1 Eyeball on this job. 
 
Why bother with the Mk. 1 Eyeball if one has available a Mk. 2 Eyeball?
Peace...  Sridhar