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It is an Avanti(Zenith usually did not put the cabinet name on their sets), and a good one...That if I'm correct is the SS horizontal flat chassis that can keep working come hell fire or high water.
That 'stretched' effect on the image is a vertical linearity issue. The way I see it the entire image above his waist is stretched or the entire area below his waist is compressed(depending on how you look at it). That can likely be cured by feeding a pattern of evenly spaced horizontal bars to the set and adjusting the Vertical height and linearity controls until the spacing of the bars on screen is even(you may have to tweak the vertical centering too).
If it is going blue with different brightness settings then you need to readjust CRT bias. With a blank raster turn the brightness and color level controls to minimum, flip the service switch on the back to collapse the vertical deflection, and turn all the rear screen(sometimes labeled G2) controls to minimum(for this part have a mirror set up so you can watch the set while adjusting the rear controls) then turn red up until a dim red line appears, turn the green back up until you have yellow, and turn the blue back up until you have white, flip the service switch back to normal position to reactivate vertical deflection, and turn brightness up until satisfactory. Now play a gray scale test pattern, and if the gray scale is still tinted there should be some red,green,blue level controls other than the screen controls to adjust tweak those to kill the tint in the monochrome picture. Make sure you also dial in the brightness and contrast to acceptable levels.
After that is done turn the color level up and place a color bars test pattern on the screen and adjust hue and color level for most accurate reasonably saturated color, switch to live action content and tweak hue and possibly color level controls for good skin tones if need be.
The problem with that white line is one of two things. It is either a convergence or usually in curable video design limitation. Get a test pattern with wider monochrome cross hatched bars and see if the bars are color fringed or pure white when displayed. If fringed readjust convergence. If the fringes disappear then what is happening is that the vertical line you were displaying is so thin that the frequency of the pulse representing it is high enough to be above the cutoff of the high pass filter for the chroma circuits and thus cause monochrome noise to leak into chroma circuits. This set predates comb and notch filters so color noise gets into the black and white image and black and white noise gets into the color circuits by the limitations of the design.
There are probably adjustments for the chromatic somewhere. The chromatic was basically just another set of controls for brightness contrast, hue, and color level that could be switched in in place of the user controls so that if someone monkeyed with the user controls and you were in a hurry or you could not get them right your self you could push the button to 'fix it'. The chromatic adjustments drift with time and when you resetup the set like the above screens adjustment I mentioned.
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